tag:theconversation.com,2011:/fr/topics/spider-silk-7153/articlesSpider silk – The Conversation2022-03-16T12:41:43Ztag:theconversation.com,2011:article/1792302022-03-16T12:41:43Z2022-03-16T12:41:43ZHow spider silk could one day be used in cancer treatment – new research<figure><img src="https://images.theconversation.com/files/452266/original/file-20220315-17-enttzk.jpg?ixlib=rb-1.1.0&rect=40%2C13%2C4500%2C2977&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/spider-climbs-on-web-1177846123">Vadym Lesyk/Shutterstock</a></span></figcaption></figure><p>Cancer is simultaneously one of the most common and devastating diseases in our society. So working out new ways to treat it is an enduring scientific challenge.</p>
<p>A protein called p53 plays <a href="https://ki.se/en/research/p53-the-guardian-of-the-genome">a key role</a> in the body’s immune response to cancer, and therefore makes an interesting target for cancer treatment. Specifically, our bodies rely on p53 to prevent cancer cells from growing and dividing uncontrollably.</p>
<p>P53 has been called the “guardian of the genome” because it can stop cells with DNA damage turning into cancer cells. Essentially, it shuts down the cell if it detects any damage that could cause cells to grow into tumours.</p>
<p>In up to <a href="https://www.nature.com/articles/cdd2017180">60% of all cancers</a>, p53 is missing or damaged, making this the most common feature shared across human cancers. So introducing intact p53 protein into cancer cells would be an elegant way of treating the disease.</p>
<p>This is more difficult than it sounds, though. P53 is a relatively large and floppy protein, which means our cells do not produce large amounts of it, it can easily clump together and stop working, and it is quickly broken down once it has been made.</p>
<p>To find a possible solution to this problem, we looked at how nature deals with similar proteins. Somewhat unexpectedly, <a href="https://www.nature.com/articles/nchembio.1789">spidroins</a>, the proteins that spiders spin into silk, are a bit like p53. They, too, are large, floppy, and easily clump together. But unlike p53, they are capped by a small, compact part (called a domain) that is very stable and can easily be made by the cellular protein production machinery.</p>
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Read more:
<a href="https://theconversation.com/cancer-treatment-personalised-blood-tests-can-better-detect-dna-from-tumours-in-the-body-new-research-140777">Cancer treatment: personalised blood tests can better detect DNA from tumours in the body – new research</a>
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<p>In <a href="https://www.cell.com/structure/fulltext/S0969-2126(22)00049-1?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0969212622000491%3Fshowall%3Dtrue">our study</a>, which has recently been published in the journal Structure, we attached a small section of a spider silk protein – a domain – onto the human p53 protein. When we introduced this “fusion protein” to cells in the lab, we found that the cells produced it in very large amounts.</p>
<p>To understand why, we analysed the protein with electron microscopy, computer simulations, nuclear magnetic resonance, and mass spectrometry. These experiments tell us where the different parts of the protein are located, and how they work together, like parts of a robot. </p>
<p>It turned out that the floppiest part of the p53 protein was wrapped around the spider silk domain like a thread around a spindle. By “winding up” the protein like that, the spider silk domain pulled it out from the cellular production machinery, and as a result, more protein was produced.</p>
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<img alt="An illustration of the p53 protein." src="https://images.theconversation.com/files/452279/original/file-20220315-23-1n65a6z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/452279/original/file-20220315-23-1n65a6z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/452279/original/file-20220315-23-1n65a6z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/452279/original/file-20220315-23-1n65a6z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/452279/original/file-20220315-23-1n65a6z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/452279/original/file-20220315-23-1n65a6z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/452279/original/file-20220315-23-1n65a6z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">The p53 protein is found in cells, where its role is to discover and prevent genetic mutations that can lead to cancer.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/p53-tumor-suppressor-protein-prevents-cancer-1125190586">Juan Gaertner/Shutterstock</a></span>
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<p>To test if the spider silk-p53 protein is active, we put it into cancer cells that contain so-called “reporter genes”, which cause the cell to light up if p53 turns on genes that make the cell stop growing. To our surprise, the fusion protein gave a stronger response than normal p53, which means that we could in principle use the spider silk domain to increase the ability of p53 to shut down cancer cells.</p>
<h2>What now?</h2>
<p>None of our findings so far amount to a new cancer therapy. But they do open up new possibilities: we could use this knowledge to design new protein domains that make p53 less floppy and easier to produce.</p>
<p>If we deliver the RNA, the genetic “blueprint” for how to make p53, into cells, we could include modified spider silk domains to increase the cells’ ability to make the protein. </p>
<p>As next steps, we will test how well healthy human cells tolerate the spider silk proteins, and whether this addition extends the lifetime of the p53 protein inside the cells.</p>
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Read more:
<a href="https://theconversation.com/spiders-are-threatened-by-climate-change-and-even-the-biggest-arachnophobes-should-be-worried-122666">Spiders are threatened by climate change – and even the biggest arachnophobes should be worried</a>
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<p class="fine-print"><em><span>Michael Landreh does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>We’ve found an unusual way of stabilising the cancer-suppressing protein p53.Michael Landreh, Researcher, Department of Microbiology, Tumor and Cell Biology, Karolinska InstitutetLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1628522021-06-16T04:23:09Z2021-06-16T04:23:09ZSpiders are cloaking Gippsland with stunning webs after the floods. An expert explains why<figure><img src="https://images.theconversation.com/files/406637/original/file-20210616-21-fbnp54.png?ixlib=rb-1.1.0&rect=0%2C7%2C1577%2C1147&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Darren Carney</span></span></figcaption></figure><p>Stunning photographs of vast, ghostly spider webs blanketing the flood-affected region of Gippsland in Victoria have gone viral online, prompting many to muse on the wonder of nature. </p>
<p>But what’s going on here? Why do spiders do this after floods and does it happen everywhere?</p>
<p>The answer is: these webs have nothing to do with spiders trying to catch food. Spiders often use silk to move around and in this case are using long strands of web to escape from waterlogged soil. </p>
<p>This may seem unusual, but these are just native animals doing their thing. It’s crucial you don’t get out the insecticide and spray them. These spiders do important work managing pests, so by killing them off you would be increasing the risk that pests such as cockroaches and mosquitoes will get out of control.</p>
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Read more:
<a href="https://theconversation.com/after-the-floods-stand-by-for-spiders-slugs-and-millipedes-but-think-twice-before-reaching-for-the-bug-spray-157600">After the floods, stand by for spiders, slugs and millipedes – but think twice before reaching for the bug spray</a>
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<h2>Using silk to move around</h2>
<p>What you’re seeing online, or in person if you live locally, is an amazing natural phenomena but it’s not really very complicated.</p>
<p>We are constantly surrounded by spiders, but we don’t usually see them. They are hiding in the leaf litter and in the soil.</p>
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<a href="https://images.theconversation.com/files/406644/original/file-20210616-25-16tan1n.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Spider webs blanket the ground in Gippsland" src="https://images.theconversation.com/files/406644/original/file-20210616-25-16tan1n.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/406644/original/file-20210616-25-16tan1n.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=447&fit=crop&dpr=1 600w, https://images.theconversation.com/files/406644/original/file-20210616-25-16tan1n.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=447&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/406644/original/file-20210616-25-16tan1n.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=447&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/406644/original/file-20210616-25-16tan1n.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=562&fit=crop&dpr=1 754w, https://images.theconversation.com/files/406644/original/file-20210616-25-16tan1n.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=562&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/406644/original/file-20210616-25-16tan1n.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=562&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">When floods happen, spiders use silk to evacuate quickly.</span>
<span class="attribution"><span class="source">Darren Carney</span></span>
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<p>When these flood events happen, they need evacuate quickly up out of holes they live in underground. They come out en masse and use their silk to help them do that. </p>
<p>You’ll often see juvenile spiders let out a long strand of silk which is caught by the wind and lifted up. The web catches onto another object such as a tree and allows the spider to climb up.</p>
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<p>That’s how baby spiders (spiderlings!) disperse when they emerge from their egg sacs — it’s called ballooning. They have to disperse as quickly as possible because they are highly cannibalistic so they need to move away from each other swiftly and find their own sites to hunt or build their webs. </p>
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<span class="caption">Small spiders have been seen on a post in Gippsland after floods.</span>
<span class="attribution"><span class="source">AAP Image/JEFF HOBBS</span></span>
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<p>That said, I doubt these webs are from baby spiders. It is more likely to be a huge number of adult spiders, of all different types, sizes and species. They’re all just trying to escape the flood waters. These are definitely spiders you don’t usually see above ground so they are out of their comfort zone, too.</p>
<p>This mass evacuation of spiders, and associated blankets of silk, is not a localised thing. It is seen in other parts of Australia and around the world after flooding.</p>
<p>It just goes to show how versatile spider silk can be. It’s not just used for catching food, it’s also used for locomotion and is even used by some spiders to lay a trail so they don’t get lost.</p>
<h2>Don’t spray them!</h2>
<p>The most important thing I need readers to know is that this is not anything to be worried about. The worst thing you could do is get out the insecticide and spray them. </p>
<p>These spiders are making a huge contribution to pest control and you would have major pest problems if you get rid of all the spiders. The spiders will disperse on their own very quickly. In general, spiders don’t like being in close proximity to each other (or humans!) and they want to get back to their homes underground. </p>
<p>If you live in Gippsland, you probably don’t even need to clear the webs away with a broom. There’s no danger in doing so if you wish, but I am almost certain these webs will disperse on their own within days.</p>
<p>Until then, enjoy this natural spectacle. I wish I could come down to see them with my own eyes!</p>
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Read more:
<a href="https://theconversation.com/city-spiders-are-getting-bigger-but-thats-a-good-thing-30605">City spiders are getting bigger — but that's a good thing</a>
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<p class="fine-print"><em><span>Lizzy Lowe is a Senior Extension Scientist at Cesar Australia. </span></em></p>What’s going on here? Why do spiders do this after floods and does it happen everywhere?Lizzy Lowe, Researcher, Macquarie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1625302021-06-10T13:58:28Z2021-06-10T13:58:28ZNew material inspired by spider silk could help solve our plastic problem<figure><img src="https://images.theconversation.com/files/405662/original/file-20210610-27-utgyu1.jpg?ixlib=rb-1.1.0&rect=235%2C226%2C5330%2C3245&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/single-use-plastic-waste-issue-fruits-1489079006">Shutterstock/Olga Miltsova</a></span></figcaption></figure><p>Plastics are very useful materials. They’ve contributed significant benefits to modern society. But the unprecedented amount of plastics produced over the past few decades has caused serious environmental pollution. </p>
<p>Packaging alone was responsible for <a href="https://doi.org/10.1016/j.progpolymsci.2021.101395">46% out of 340 million tonnes</a> of plastic waste generated globally in 2018. Although plastic recycling has increased significantly in recent years, most plastics used today are single use, non-recyclable and non-biodegradable.</p>
<p>The demand for food will double by 2050. This will probably increase the amount of waste from food and its plastic packaging, putting poorer countries under tremendous pressure to manage waste disposal. </p>
<p>To tackle the issues of environmental damage, we need more sustainable materials that we can recycle or that biodegrade. There’s been a surge in plant-based plastics, but many of these can only be composted using industrial processes, not by people at home. </p>
<p>Now <a href="https://www.nature.com/articles/s41467-021-23813-6">researchers</a> at the University of Cambridge have found a way to make plastic from abundant and sustainable plant proteins. Inspired by spider silk, the film works in a way similar to other plastics, but it can be composted at home.</p>
<h2>Types of plastic</h2>
<p>Synthetic and non-biodegradable plastics commonly used for food packaging include polythene terephthalate (PET), polystyrene (PS) and crystalline polythene terephthalate (CPET). </p>
<p>There are some processes in place for disposing of PET – namely mechanical and <a href="https://theconversation.com/plastic-pollution-how-chemical-recycling-technology-could-help-fix-it-156346">chemical recycling techniques</a> – but most plastic around the world is <a href="https://theconversation.com/what-happens-to-the-plastic-you-recycle-researchers-lift-the-lid-142831">still sent to landfills</a>. PET can take hundreds of years to decompose and it’s non-biodegradable. This means it can continue to pollute the ecosystem for many years. </p>
<p>Making plastic requires lots of energy. Then, when plastics are thrown away, they cause environmental damage, including global warming, greenhouse gas emissions and damage to marine life. </p>
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Read more:
<a href="https://theconversation.com/what-happens-to-the-plastic-you-recycle-researchers-lift-the-lid-142831">What happens to the plastic you recycle? Researchers lift the lid</a>
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<p>On the other hand, there are some biodegradable <a href="https://theconversation.com/sustainable-lego-plastics-from-plants-wont-solve-a-pollution-crisis-92953">plant-based plastics</a>, such as polylactic acid (PLA), polybutylene succinate (PBS), polycaprolactone) (PCL) and polyhydroxyalkanotes (PHAs), which are friendlier to the environment than non-renewable polymers. </p>
<p>PLA polymers are produced from renewable resources and have the advantage of being <a href="https://theconversation.com/how-plastics-made-from-plants-could-be-the-answer-to-the-worlds-waste-problem-89475">recyclable and compostable</a>. This makes PLA a much more environmentally friendly material than PET, PS and CPET. However, their long-term durability and stability are lower than their synthetic counterparts.</p>
<h2>The new material</h2>
<p>The new research has investigated the potential use of a biodegradable and renewable polymer, such as soy protein, to make a new material that could be an alternative to other plant-based plastics. </p>
<p>The researchers created a plant-based plastic and added nanoparticles – particles smaller than one millionth of a metre. This meant they could control the structure of the material to create flexible films, with a material that looks like spider silk on a molecular level. They’ve called it a “vegan spider silk”.</p>
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<img alt="Two small cardboard boxes with plastic film inside them." src="https://images.theconversation.com/files/405664/original/file-20210610-19-1wqu2g3.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/405664/original/file-20210610-19-1wqu2g3.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/405664/original/file-20210610-19-1wqu2g3.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/405664/original/file-20210610-19-1wqu2g3.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/405664/original/file-20210610-19-1wqu2g3.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/405664/original/file-20210610-19-1wqu2g3.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/405664/original/file-20210610-19-1wqu2g3.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">The new material in action.</span>
<span class="attribution"><span class="source">Xampla</span></span>
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<p>The team used various techniques, including scanning electron microscopy and transmission electron microscopy to study the structure of the film.</p>
<p>They analysed important properties, such as barrier properties and moisture absorption. They found the nanoparticles helped to increase the various properties – strength and long-term durability and stability – significantly. </p>
<p>By creating a plastic with a more environmentally friendly manufacturing process, made from sustainable materials itself, a significant amount of energy can be saved. This is one of the most exciting parts of this study. </p>
<p>This new material could help solve some of the problems that plastic pollution has caused to the environment – by introducing a material from renewable source with enhanced properties suitable for many engineering applications, including packaging.</p>
<p>The study could help to scale up the production of sustainable packaging materials, using natural resources and less energy consumption, while reducing the amount of plastic going into landfill.</p><img src="https://counter.theconversation.com/content/162530/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Hom Dhakal does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The film is similar to other plastics, but it can be composted at home.Hom Dhakal, Professor of Mechanical Engineering, University of PortsmouthLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1535612021-02-10T13:13:48Z2021-02-10T13:13:48ZSpider legs build webs without the brain’s help – providing a model for future robot limbs<figure><img src="https://images.theconversation.com/files/383377/original/file-20210209-23-10gewzg.jpg?ixlib=rb-1.1.0&rect=35%2C0%2C4000%2C2658&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/european-garden-spider-diadem-orangie-cross-1805537293">Erik Karits/Shutterstock </a></span></figcaption></figure><p>Arachnophobes often cite spiders’ unpredictable movement as the basis of their fear, pointing out how each spindly leg seems to lift, flex and probe with a menacing degree of autonomy. </p>
<p>Perhaps unsettlingly, my colleague Thiemo Krink and I have conducted research that reveals that each one of a spider’s legs does indeed enjoy a certain independence from the brain – especially in the complex task of web-building. </p>
<p><a href="https://royalsocietypublishing.org/doi/10.1098/rsif.2020.0569">Our study</a> has shown that spider legs have “minds of their own”, constructing webs without the oversight of the spider’s brain. This has important implications for the field of robotics, which may take inspiration from this example of decentralised intelligence to build similarly autonomous robot limbs.</p>
<p>To arrive at our conclusions, we observed the common garden spider <em>Araneus diadematus</em>, a creature familiar to us all – both suspended in our back yards, and as the heroine within the pages of the children’s book Charlotte’s Web.</p>
<h2>Web engineers</h2>
<p>Spiders’ webs serve many functions. They provide a safe home, but they’re also famously an invisible and highly dynamic trap set up to capture and then firmly hold any insect that strays too close. </p>
<p>To perform this function, webs use a a <a href="https://onlinelibrary.wiley.com/doi/full/10.1002/adma.201401027">strong structural scaffold</a> of radiating spokes with what’s called a “capture spiral” built on top, which is soft and sticky and uses an extremely clever microscopic <a href="https://www.youtube.com/watch?v=cnbhsWtL4ks">reeling mechanism</a> to pull in a spider’s prey. </p>
<p>Not only does the capture spiral use <a href="https://www.youtube.com/watch?v=iV_HsWWt6_o&ab_channel=OxfordSilkGroup">electrostatic charges</a> to trap a fly, it features a complex glue to hold it firmly, and a <a href="https://www.youtube.com/watch?v=Kjh7bQSc8ag&ab_channel=OxfordSilkGroup">specific elasticity</a> that makes the web too stretchy for the leg of a hapless insect to push against in its struggle for freedom.</p>
<p>The analogy of the internet as a “web” is a fine one: because at least five different silks are used in a spider’s web, the way they intersect and network with one another creates a kind of <a href="https://academic.oup.com/icb/article-abstract/59/6/1636/5491829">information filtering capacity</a> – with tiny vibrations noted at all times by a spider’s listening legs.</p>
<h2>Spider diagram</h2>
<p>Given the incredible complexity of spiders’ webs we must ask how such a small animal – with an obviously minute brain – can design and build this advanced structure. Modern technology has helped us begin to understand how spiders manage such a complex task. </p>
<p>By filming and tracking the movements of its eight legs, we have been able to track a spider’s web-building in intimate detail, revealing the construction process to be a kind of dance around a central hub, with a precise choreography of replicable rules.</p>
<p>These rules are surprisingly simple. Each step and thread manipulation follows a fixed action pattern, with one of the spider’s legs measuring an angle and a distance in order to place and then connect one thread to another with a quick dab of glue – always with impeccable accuracy and spacing. Many years ago, we programmed a virtual spider, named Theseus, to demonstrate how this works.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/HcDurM4uP-s?wmode=transparent&start=66" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Theseus the virtual spider, introduced here by the lead author of the Theseus project, Dr Thiemo Krink.</span></figcaption>
</figure>
<p>The apparent complexity of the structure is the result of a long sequence of thousands of small steps and actions, each building on the previous steps and actions. This iterative process invests the network with “emergent properties” – special properties that manifest as the result of different components working together – which in turn provide outstanding architectural and engineering functionality.</p>
<h2>Outsourcing</h2>
<p>The complexity of the task at hand (or rather foot) when building a web seems to have required spider brains to outsource the work to the eight legs. Put another way, spider legs build webs semi-autonomously – eight phantom limbs performing their dance within local, closed feedback loops. </p>
<p>We discovered this after studying spiders building webs within frames in our laboratory. In some experiments, we cut out threads of a web being built. In others, we rotated the web like a ferris wheel. This probing wasn’t done to annoy the spider: it was to help us discern the rules that govern web building.</p>
<p>With a set of rules established – including rules that help spiders continue to build a disrupted web – we taught them to Theseus, our virtual spider. </p>
<p>The new rules we taught Theseus – based on the dances of real spiders we observed in our lab – revealed that each leg actually conducts many web-building actions as <a href="https://royalsocietypublishing.org/doi/10.1098/rsif.2020.0569">an independent agent</a>. This in turn helped us solve the mystery of how spiders build perfect webs after the loss of a leg. </p>
<p>When a spider’s leg becomes trapped, it’s discarded, and a shorter leg regenerates the next time the spider moults its exoskeleton. Not only is this replacement half the size of a normal leg, it’s also a different shape, with different hairs and sensors. Yet somehow spiders with regenerated legs continue to build perfect webs.</p>
<figure class="align-center ">
<img alt="A small spider against a black background on its web" src="https://images.theconversation.com/files/383372/original/file-20210209-23-w7b7i6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/383372/original/file-20210209-23-w7b7i6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=446&fit=crop&dpr=1 600w, https://images.theconversation.com/files/383372/original/file-20210209-23-w7b7i6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=446&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/383372/original/file-20210209-23-w7b7i6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=446&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/383372/original/file-20210209-23-w7b7i6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=561&fit=crop&dpr=1 754w, https://images.theconversation.com/files/383372/original/file-20210209-23-w7b7i6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=561&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/383372/original/file-20210209-23-w7b7i6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=561&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A common garden spider with regenerated legs on its left side.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Evolution has seen to it that spider legs can in some sense think for themselves, which means the different properties of regenerated legs does not affect the building of a web.</p>
<p>This relieves the brain from micromanaging eight legs executing complicated activities, freeing it to focus on survival actions such as looking out for predators. This efficient, decentralised system is remarkably relevant for modern roboticists – who are often inspired by the natural world in their artificial designs. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-do-robots-look-like-animals-and-humans-96967">Why do robots look like animals and humans?</a>
</strong>
</em>
</p>
<hr>
<p>Spiders are not alone in decentralising tasks from the brain – indeed, most animals do it to some extent, like the continuous beating of a human heart. But with their webs, spiders provide us with a concrete, observable, and mesmerising means of measuring and understanding how this decentralisation works.</p>
<p>This neat trick lies in a spider’s embedding of simple task computation within the structure of its limbs. Roboticists call this morphological computing, and have only relatively recently discovered its power. The humble garden spider, it turns out, has been using it for well over 100 million years.</p><img src="https://counter.theconversation.com/content/153561/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Fritz Vollrath receives funding from The Leverhulme Foundation and European Research Council (ERC) as well as Air Force Office of Scientific Research (AFOSR), UK Science Research Councils, Royal Society, Volkswagen Stiftung and Danish National Research Fund (DNRF), </span></em></p>Unsettlingly, it appears that spiders’ legs really do have minds of their own.Fritz Vollrath, Emeritus Professor, Department of Zoology, University of OxfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1077732019-06-05T14:03:09Z2019-06-05T14:03:09ZSpider glue’s sticky secret revealed by new genetic research<figure><img src="https://images.theconversation.com/files/277969/original/file-20190604-69071-x7jm95.jpg?ixlib=rb-1.1.0&rect=844%2C62%2C4778%2C3592&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Spider glue is actually a specialized silk protein.</span> <span class="attribution"><span class="source">Sarah Stellwagen</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>What do all of the <a href="https://wsc.nmbe.ch/">over 45,000 described spider species</a> on Earth have in common? Each makes at least one type of silk. And there are an awful lot of types out there.</p>
<p>An individual orb weaving spider – the kind that spins the classic two-dimensional aerial spiral webs that seem to always be suspended at human face-height – can produce seven different silks, each with unique material properties.</p>
<p>Dragline silk forms the frame of an orb web and is famous for its strength and toughness, <a href="https://www.sciencemag.org/news/2018/11/spider-silk-five-times-stronger-steel-now-scientists-know-why">comparable to that of steel</a>. The capture spiral is made of a highly stretchy version called flagelliform silk. Orb weaving spiders use an additional type of silk to wrap prey and create web decorations.</p>
<p>But there’s another kind that, on the surface, doesn’t resemble silk at all: the sticky glue with which some spiders cover their silk capture threads. It doesn’t look like the classic threads that come to mind when thinking of spider silk, but the gluey substance from these webs is in fact a silk protein.</p>
<p>For many years, researchers have been uncovering the secrets of spider glue, which stays wet in its open air environment and sticky over many rounds of attachment and release. Its genetic blueprint has remained elusive, however, meaning scientists haven’t been able to think about setting up large-scale production of this potentially useful biomaterial. </p>
<p>Using new technology, my colleague and <a href="https://scholar.google.com/citations?user=gWWab2oAAAAJ&hl=en&oi=ao">I have been able</a> to sequence the <a href="https://doi.org/10.1534/g3.119.400065">first full genetic sequences</a> that code for spider glue proteins.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/277968/original/file-20190604-69059-a0pc48.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/277968/original/file-20190604-69059-a0pc48.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/277968/original/file-20190604-69059-a0pc48.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=354&fit=crop&dpr=1 600w, https://images.theconversation.com/files/277968/original/file-20190604-69059-a0pc48.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=354&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/277968/original/file-20190604-69059-a0pc48.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=354&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/277968/original/file-20190604-69059-a0pc48.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=445&fit=crop&dpr=1 754w, https://images.theconversation.com/files/277968/original/file-20190604-69059-a0pc48.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=445&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/277968/original/file-20190604-69059-a0pc48.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=445&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Spider glue drops spread along a strand of capture spiral silk.</span>
<span class="attribution"><span class="source">Sarah Stellwagen</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>A silk that’s really a sticky glue</h2>
<p>Under a microscope, orb weaver glue resembles beads on a string – little glistening spheres along a strand of stretchy support silk. Instead of being spun into a fiber as it leaves the spider’s body like other silks, the glue proteins are extruded as a jumbled mass. Their job is to stickily retain prey that get caught in the web.</p>
<p>Different spider species produce glue tailored to their habitat’s conditions and prey.</p>
<p>The glue of tropical orb weaving species is sticky in the spider’s wet habitat, but downgrades to just tacky in low humidity. The glue of orb weavers from dry regions becomes dilute and thin if the humidity is too high.</p>
<p>Bolas spiders forgo the orb web, and instead produce a large globule of glue at the end of a long strand of silk that they whirl rapidly through the air. The glue of this sticky snare is specialized for capturing moths covered with loose scales.</p>
<p>Widow spiders produce vertical, glue-covered trip lines that detach from the ground when encountered by an unsuspecting victim, springing the prey into the air where it hangs suspended. Unlike orb weaver glue, widow glue is resistant to fluctuating humidity.</p>
<p>These various specialized adhesive properties have intrigued biomaterials researchers who can dream up plenty of uses for artificial versions of spider glues. But without knowing the genes that code for these proteins, there hasn’t been a clear road map for how to produce synthetic spider glues.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/277994/original/file-20190604-69059-7uxi6o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/277994/original/file-20190604-69059-7uxi6o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/277994/original/file-20190604-69059-7uxi6o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/277994/original/file-20190604-69059-7uxi6o.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/277994/original/file-20190604-69059-7uxi6o.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/277994/original/file-20190604-69059-7uxi6o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/277994/original/file-20190604-69059-7uxi6o.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/277994/original/file-20190604-69059-7uxi6o.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Their sticky glue is part of what makes spiders’ webs so hard to escape.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/banded-garden-spider-argiope-trifasciata-grasshopper-1229048797">Robert Mutch/Shutterstock.com</a></span>
</figcaption>
</figure>
<h2>Cracking a long, repetitive code</h2>
<p>Surprisingly, researchers have only sequenced around 20 full-length spider silk genes despite the incredible diversity of spiders and decades-old interest in <a href="https://www.newyorker.com/tech/annals-of-technology/in-the-future-well-all-wear-spider-silk">silk as a useful biomaterial</a>.</p>
<p>It turns out that not only are the properties of spider silk amazing, but so is the DNA code that stores the instructions for making the protein. Spider silk genes are extremely large; in itself that’s not a problem, but the bulk of their sequence is made from repeats of the same small DNA bits.</p>
<p>Imagine that the sentence “THE QUICK BROWN FOX JUMPED OVER THE LAZY DOG” is a sequence of DNA that encodes for a protein, but whose exact order of letters is still unknown.</p>
<p>In order to discover this sequence, the main method of DNA sequencing technology available today has three main steps. Once a DNA sample is collected, many copies of the sentence are randomly broken up into small pieces. For example, you might end up with a collection of fragments like “THE QU” “QUICK B” “BROWN FO” “WN FOX J” “AZY DOG” and on and on.</p>
<p>Then a DNA sequencing machine discovers each letter of each piece. The final step is stitching all the short pieces, technically called “reads,” back together in one sequence to figure out the original sentence.</p>
<p>For the sentence above, this is an easy task. The sequence of letters is unique, and as long as there are at least five characters in each read, it’s possible to figure out where one fits relative to another.</p>
<p>Now imagine a similar sentence: “THE QUICK BROWN FOX JUMPS JUMPS JUMPS JUMPS JUMPS JUMPS JUMPS JUMPS JUMPS JUMPS JUMPS OVER THE LAZY DOG.” Given many random short reads from the middle region like “UMPS J” or “S JUMP,” no matter how you slice and dice, it’s impossible to use this method to figure out the number of “JUMPS” in the complete sentence. </p>
<h2>Sequencing a long read of DNA in one go</h2>
<p>For many years DNA sequencing has been limited to this short-read strategy: breaking a gene into bits and then reassembling into one cohesive sequence.</p>
<p>Setting aside some difficult and expensive techniques that are out of reach for standard labs, the best way to fully discover a long, repetitive gene is to sequence the repetitive part from start to finish in one go. Fortunately, emerging technology, while still in its infancy, is starting to allow this long-read sequencing by getting around the chemistry limitations of the short-read method. For those that study super-repetitive DNA this is excellent news: New types of DNA sequencers are finally resolving the “JUMPS.”</p>
<p>Now that <a href="https://doi.org/10.1534/g3.119.400065">two spider glue genes are fully sequenced</a>, the first step towards making a synthetic version is complete. Researchers can now insert the genes into other organisms, like bacteria or yeast, to make the glue in bulk.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/277981/original/file-20190604-69059-1fe6qme.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/277981/original/file-20190604-69059-1fe6qme.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/277981/original/file-20190604-69059-1fe6qme.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=402&fit=crop&dpr=1 600w, https://images.theconversation.com/files/277981/original/file-20190604-69059-1fe6qme.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=402&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/277981/original/file-20190604-69059-1fe6qme.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=402&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/277981/original/file-20190604-69059-1fe6qme.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=505&fit=crop&dpr=1 754w, https://images.theconversation.com/files/277981/original/file-20190604-69059-1fe6qme.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=505&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/277981/original/file-20190604-69059-1fe6qme.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=505&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Droplet of spider glue suspended on capture spiral silk (left) and after adhering to a glass slide (right).</span>
<span class="attribution"><span class="source">Sarah Stellwagen</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Unlike solid silks, the glue proteins do not have to be transformed from a liquid to a solid fiber, something spiders do effortlessly but that scientists have trouble replicating. The glue has the potential for many unique applications and is biodegradable, water soluble and stays sticky for months or even years.</p>
<p>Imagine safer pest control or washable filters. Or frat boys wrestling in a kiddie pool of the stuff. Either way, someday soon it might be possible to reach your hand into a bucket of spider glue – the tricky part will be not sticking to whatever you touch next.</p><img src="https://counter.theconversation.com/content/107773/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sarah Stellwagen does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The glue that gives spider webs their stickiness is a form of spider silk protein. Researchers can imagine cool uses for a synthetic version – but had to wait for the tricky glue gene to be sequenced.Sarah Stellwagen, Postdoctoral Researcher in Biological Sciences, University of Maryland, Baltimore CountyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1162432019-05-03T14:57:31Z2019-05-03T14:57:31ZCurious Kids: why is spider silk so easy to break when it’s supposedly stronger than steel?<figure><img src="https://images.theconversation.com/files/272497/original/file-20190503-103049-wqai3n.jpg?ixlib=rb-1.1.0&rect=0%2C108%2C4256%2C2714&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Web of flies. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/beautiful-cobweb-dew-on-winter-morning-1291611304">Shutterstock.</a></span></figcaption></figure><figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=376&fit=crop&dpr=1 600w, https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=376&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=376&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=472&fit=crop&dpr=1 754w, https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=472&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=472&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p><em><a href="https://theconversation.com/au/topics/curious-kids-36782">Curious Kids</a> is a series by <a href="https://theconversation.com/uk">The Conversation</a>, which gives children of all ages the chance to have their questions about the world answered by experts. All questions are welcome: you or an adult can send them – along with your name, age and town or city where you live – to curiouskids@theconversation.com. We won’t be able to answer every question, but we’ll do our best.</em></p>
<hr>
<p><em><strong>How is spider silk so easy to break when it’s stronger than steel? - George, aged ten, Hethersett, UK.</strong></em></p>
<p>Thanks for the question, George – the simple answer is that spider silk breaks easily because it’s really, really, <em>really</em> thin. A thread in the web of a garden spider is <a href="https://www.earthlife.net/chelicerata/silk.html">just 0.003 millimetres across</a> – that’s more than 20 times thinner than a hair from your head. </p>
<p>But there are a few more matters we need to untangle, to see how strong spider silk is, compared with steel. </p>
<p>Steel is a material called an <a href="https://www.bbc.com/bitesize/guides/z8db7p3/revision/2">alloy</a>, which means it is a mixture of metals. The main metal in steel is iron. Other metals are added to the iron, depending on what you want the steel to do. </p>
<p>For example, knives and forks are made from stainless steel that doesn’t rust. To make this you’d mix iron and chromium. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/272494/original/file-20190503-103082-1nct2ud.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/272494/original/file-20190503-103082-1nct2ud.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=379&fit=crop&dpr=1 600w, https://images.theconversation.com/files/272494/original/file-20190503-103082-1nct2ud.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=379&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/272494/original/file-20190503-103082-1nct2ud.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=379&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/272494/original/file-20190503-103082-1nct2ud.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=476&fit=crop&dpr=1 754w, https://images.theconversation.com/files/272494/original/file-20190503-103082-1nct2ud.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=476&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/272494/original/file-20190503-103082-1nct2ud.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=476&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The Sydney harbour bridge is made from steel.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/paulcarmona/15805655240/sizes/l">SydneyLens/Flickr.</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>But maybe you want a steel that is really strong so you could make buildings and cranes from it. Then, you would need to mix iron with a load of different metals including titanium and vanadium. </p>
<p>But there are even stronger steels. Your bike might be built with something called maraging steel and it’s made with iron, nickel, cobalt, molybdenum, titanium and aluminium.</p>
<h2>Spiders’ different silks</h2>
<p>Silk is a very different material from steel. It is actually <a href="https://www.educationquizzes.com/gcse/biology/unit-2-proteins/">protein</a> – the same stuff that your hair and finger nails are made from. </p>
<p>We use steel for different jobs and spiders use silk for all sorts of things as well. And the just like our steel, spiders need different silks for the different jobs. </p>
<p>Let’s look at the <a href="http://britishspiders.org.uk/wiki2015/index.php?title=Araneus_diadematus">common European garden spider</a>: this lovely creature spins the beautiful round webs, using two types of silk. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/272498/original/file-20190503-103057-l88nd7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/272498/original/file-20190503-103057-l88nd7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/272498/original/file-20190503-103057-l88nd7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/272498/original/file-20190503-103057-l88nd7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/272498/original/file-20190503-103057-l88nd7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/272498/original/file-20190503-103057-l88nd7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/272498/original/file-20190503-103057-l88nd7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Sweet little thing.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/rstehn/29946508346/sizes/l">Rüdiger Stehn/Flickr.</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>The spokes of the web are made from dragline silk. This is strong and slightly stretchy, which means it’s good for making the main supports for the web. </p>
<p>The rest of the web is made from flag silk, which is less strong but very elastic, so it is really good at absorbing the shock when a great big fly smashes into the web. </p>
<p>But the champion constructor of the spider world is the <a href="http://www.bbc.co.uk/earth/story/20151126-the-worlds-biggest-spider-web-can-span-an-entire-river">Darwin bark spider</a>. It produces huge webs, about the size of a kitchen table. </p>
<p>These are sometimes hung from trees with silk threads that stretch right across rivers. To make sure these webs stay in place, the spider uses super strong threads of silk. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/272493/original/file-20190503-103071-as9kq4.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/272493/original/file-20190503-103071-as9kq4.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=422&fit=crop&dpr=1 600w, https://images.theconversation.com/files/272493/original/file-20190503-103071-as9kq4.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=422&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/272493/original/file-20190503-103071-as9kq4.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=422&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/272493/original/file-20190503-103071-as9kq4.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=530&fit=crop&dpr=1 754w, https://images.theconversation.com/files/272493/original/file-20190503-103071-as9kq4.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=530&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/272493/original/file-20190503-103071-as9kq4.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=530&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A Darwin bark spider’s web stretches across a river.</span>
<span class="attribution"><a class="source" href="https://pl.wikipedia.org/wiki/Plik:Caerostris_darwini_web.png">Ingi Agnarsson, Matjaž Kuntner, Todd A. Blackledge/Wikimedia Commons.</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Now, I’ve done some calculations, based on what scientists know about the strength of these different materials, to compare steels with spider silks and see just how strong they are. </p>
<h2>The winning web</h2>
<p>Imagine we had a thread of each material, that was about one millimetre thick – that’s roughly the width of a pin head. Who could hang from them before they broke?</p>
<p>The weakest is the flag line silk: a ten-year-old girl could probably swing from a thread of this, but nothing much heavier. </p>
<p>Next comes the high strength steel which would just about be OK if a chimpanzee hung from it. </p>
<p>The dragline silk would support a small adult – like <a href="https://theconversation.com/what-does-spider-man-eat-for-breakfast-36857">Spiderman</a>. </p>
<p>The Darwin bark spider silk is next, it would break if anything much bigger than a panda tried to climb it. </p>
<p>And finally, a gorilla would be fine dangling from a one millimetre-thick thread of maraging steel. </p>
<p>Which means that some the strongest steel is actually tougher than the champion spider silks. That is a shame, but all is not lost for the spiders: remember, some of their silks are still stronger than some steels. </p>
<hr>
<p><em>More <a href="https://theconversation.com/topics/curious-kids-36782?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=CuriousKidsUK">Curious Kids</a> articles, written by academic experts:</em></p>
<ul>
<li><p><em><a href="https://theconversation.com/curious-kids-how-do-babies-learn-to-talk-111613?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=CuriousKidsUK">How do babies learn to talk? – Ella, aged nine, Melbourne, Australia.</a></em></p></li>
<li><p><em><a href="https://theconversation.com/curious-kids-why-do-pets-have-dark-eyes-while-humans-have-mostly-white-eyes-115391?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=CuriousKidsUK">Our guinea pigs have dark eyes. Why do we have white eyes? - Rhoswen, aged three, Bristol, UK.</a></em></p></li>
<li><p><em><a href="https://theconversation.com/curious-kids-whats-the-point-of-nits-116158?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=CuriousKidsUK">What’s the point of nits?! – Connie, aged nine, Nambour, Australia.</a></em></p></li>
</ul><img src="https://counter.theconversation.com/content/116243/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mark Lorch does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Spiders use different types of silk for different purposes – and not all of them are as strong as steel.Mark Lorch, Professor of Science Communication and Chemistry, University of HullLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1086022019-01-21T00:53:05Z2019-01-21T00:53:05ZCurious Kids: why do spiders have hairy legs?<figure><img src="https://images.theconversation.com/files/249892/original/file-20181211-76956-7z4a17.jpg?ixlib=rb-1.1.0&rect=0%2C10%2C3563%2C2213&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">There's a very good reason for those leg hairs.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/topaz-mcnumpty/6197581856/in/photolist-arEeaA-EBfRa-sXA5-62R872-cwKggm-dtSSu-a5kap8-hpvmLR-XQNvhb-dM2t6h-pRabSw-2bEi4XY-2NNVQC-5Dfe9m-dmxYDK-Jr9ZoV-AUbMNE-ehyoih-fDLK2j-afz3mu-6L4Ewv-GW41JH-5m13nF-Xhm2Yg-8DddAd-auftrg-n84S4M-ANFuV8-PWouh-mhFnkX-4yrsvK-9c33cd-cYMLrJ-aiALZy-5Mpkb-2VnCua-59GvE-9KUK2J-E5ptr-72vyQT-dLVTUx-8E9A42-34pz6h-bWcaJk-28VpbNG-p2UeKa-jQKEg-9iSwgX-6WNknD-nKucLk">Flickr/Hamish Irvine</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p><em><a href="https://theconversation.com/au/topics/curious-kids-36782">Curious Kids</a> is a series for children. You can send your question to curiouskids@theconversation.edu.au. You might also like the podcast <a href="http://www.abc.net.au/kidslisten/imagine-this/">Imagine This</a>, a co-production between ABC KIDS listen and The Conversation, based on Curious Kids.</em> </p>
<hr>
<blockquote>
<p><strong>Why do spiders have hairy legs? - Audrey, age 5, Fitzroy, Melbourne.</strong></p>
</blockquote>
<p>Good question, Audrey! Believe it or not, I have studied the hairy legs of spiders for years and can give you some definitive answers on this.</p>
<p>But before we talk about the spider’s fur, think about your very own hairs. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-if-a-huge-huntsman-spider-is-sucked-into-a-vacuum-cleaner-can-it-crawl-out-later-77390">Curious Kids: If a huge huntsman spider is sucked into a vacuum cleaner, can it crawl out later?</a>
</strong>
</em>
</p>
<hr>
<h2>Why do we have hair?</h2>
<p>First, there is the hair on your head, which protects you from the sun and rain. Then, there is smaller hair above your eyes – your eyebrows and eye lashes. These prevent dust from entering your eye. </p>
<p>And then have a closer look – you have all that very fine hair on your arms and legs, you can hardly see. What happens when you very, very gently touch this hair or blow at it? It tickles! This very fine body hair helps humans to feel if something is touching you. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/253797/original/file-20190115-180494-5grkf2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/253797/original/file-20190115-180494-5grkf2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/253797/original/file-20190115-180494-5grkf2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=389&fit=crop&dpr=1 600w, https://images.theconversation.com/files/253797/original/file-20190115-180494-5grkf2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=389&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/253797/original/file-20190115-180494-5grkf2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=389&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/253797/original/file-20190115-180494-5grkf2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=488&fit=crop&dpr=1 754w, https://images.theconversation.com/files/253797/original/file-20190115-180494-5grkf2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=488&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/253797/original/file-20190115-180494-5grkf2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=488&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">It looks like this spider has a beard.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/opoterser/2811403801/in/photolist-5hrbpk-5rqSBr-5sSoE8-5ybkYe-5Bbtun-5BfJdQ-52DYYU-9tNubm-7fWJLc-7aKC9h-7KhAT1-3L96aJ-auPTFK-3wThd1-7KdFzB-7DfCzx-at5r33-w7d1aa-6pyNvB-dqbKMK-4NKwSm-eeJKHY-6JdSMB-5nWn6B-295jtf3-4Pve7e-6hDGxG-4NFU8L-qVYY5j-2dC4sSg-jjfaYR-dasChi-aADySm-ebc6P5-cantCG-awyBzJ-c8EDcm-gX6QJi-7w4rCv-56BX2g-76vD1C-fVhJcj-9gU11H-ZeEw9b-2c4UuX6-MqoCv-c9N5hC-gRWdzT-bhByZR-bZGDFN">Flickr/Thomas Shahan</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>In spiders, it is quite similar. Their body hair helps them to feel if something is touching them. Say you took a paintbrush and gently touched a spider with it (don’t do this without an adult there, of course, because some spiders can be dangerous). This touch will make the spider’s hairs bend. The spider will feel that something big is touching it and probably think “Oh dear, there is something that wants to eat me!” and run off.</p>
<p>Like you, spiders have different types of hairs. But spiders can do much more cool things with their hair then we can with ours (except, maybe that we are superior in styling our hair in a cool fashion).</p>
<h2>Spidey senses</h2>
<p>Have you ever seen a spider with ears? Well, no (that would actually look funny!) That’s because spiders use hairs on their legs to listen! Sounds unbelievable, but that’s how it is.</p>
<p>Does a spider have a nose? I’ve never seen one, and I have seen lots and lots of spiders. To smell, spiders use hairs.</p>
<p>Does a spider have a tongue? Nope. They use – you guessed it – hairs!</p>
<p>So spiders can feel, listen, smell and taste with their hairy legs. Pretty cool, right? </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/253799/original/file-20190115-180482-57hm4d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/253799/original/file-20190115-180482-57hm4d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/253799/original/file-20190115-180482-57hm4d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/253799/original/file-20190115-180482-57hm4d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/253799/original/file-20190115-180482-57hm4d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/253799/original/file-20190115-180482-57hm4d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/253799/original/file-20190115-180482-57hm4d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/253799/original/file-20190115-180482-57hm4d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Spiders can hear, taste and smell with those lovely leg hairs.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/genista/2519226607/in/photolist-4QBGiv-29gjgE4-7rFxbx-5hrbpk-5rqSBr-5sSoE8-5ybkYe-5Bbtun-5BfJdQ-52DYYU-9tNubm-7fWJLc-7aKC9h-7KhAT1-3L96aJ-auPTFK-3wThd1-7KdFzB-7DfCzx-at5r33-w7d1aa-6pyNvB-dqbKMK-4NKwSm-eeJKHY-6JdSMB-5nWn6B-295jtf3-4Pve7e-6hDGxG-4NFU8L-qVYY5j-2dC4sSg-jjfaYR-dasChi-aADySm-ebc6P5-cantCG-awyBzJ-c8EDcm-gX6QJi-7w4rCv-56BX2g-76vD1C-fVhJcj-9gU11H-ZeEw9b-2c4UuX6-MqoCv-c9N5hC">Flickr/Kai Schreiber</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Some spiders can also use their hairs to grip onto a very flat surface – this is why you see spiders walking happily across a window, a ceiling or high up on a wall. (This is also how Spiderman does it, by the way).</p>
<p>Actually, not all spiders than can do that. Only the ones that have special Spiderman-hairs on their feet can do it. These Spiderman-hairs are tiny and have even tinier hairs on them – hairs on hairs. Scientists are trying to learn from these spiders and create Spiderman gloves. With such gloves you could climb up a skyscraper like a spider!</p>
<h2>Show-off spiders</h2>
<p>Spiders can be quite colourful. Do you know peacock spiders? Here is a picture of one:</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/253795/original/file-20190115-180488-1hjjjut.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/253795/original/file-20190115-180488-1hjjjut.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/253795/original/file-20190115-180488-1hjjjut.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/253795/original/file-20190115-180488-1hjjjut.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/253795/original/file-20190115-180488-1hjjjut.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/253795/original/file-20190115-180488-1hjjjut.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/253795/original/file-20190115-180488-1hjjjut.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/253795/original/file-20190115-180488-1hjjjut.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The bright parts of a peacock spider are due to its colourful hairs.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/59431731@N05/8149975545/in/photolist-dqbKMK-9iTs6j-nbuuHK-avU8KP-aUfeNM-axqk3H-awdTh1-9hGXoV-9J1h1y-dAv32Q-aUffov-9ikMcH-9jjr7Q-9hKMN4-73VQnA-9imW7K-76vD1C-aw44ut-aTxhDP-dEAWQK-auREZi-9pWmzg-axp93n-aEg51S-dtT6zo-dtT6SN-pzcVJk-auTc7B-dDFdCM-9osX9T-nbuxPz-9jjPAy-nbuxi5-nsGtjM-aAVqrd-9Va5xj-9HwNnH-aDYz3S-dDkZ3r-9t9FoE-aEg2k9-aP8qti-b2hsuK-dtx7Uw-dtx6uJ-auRfmG-9ip4yy-9Kpdic-dtT8qj-aEcci8">Flickr/Jurgen Otto</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>The peacock spider’s colours come from special hairs on its legs and body and they are used to impress other peacock spider mates and find a partner. The peacock spider boy waves his coloured hairy legs in a funky dance to tell the spider girl, “I am the best guy you’ll ever find”. Such a show-off! Here’s how they look when they dance:</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/d_yYC5r8xMI?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>So you see, spiders need hairs for quite a lot of things in their life – and that is why they have hairy legs.</p>
<hr>
<p>
<em>
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Read more:
<a href="https://theconversation.com/curious-kids-what-are-spider-webs-made-from-and-how-strong-are-they-91824">Curious Kids: What are spider webs made from and how strong are they?</a>
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</p>
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<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=376&fit=crop&dpr=1 600w, https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=376&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=376&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=472&fit=crop&dpr=1 754w, https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=472&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/165749/original/image-20170419-32713-1kyojyz.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=472&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption"></span>
<span class="attribution"><a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
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<p><em>Please tell us your name, age and which city you live in. You can send an audio recording of your question too, if you want. Send as many questions as you like! We won’t be able to answer every question but we will do our best.</em></p><img src="https://counter.theconversation.com/content/108602/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jonas Wolff is currently funded by a Discovery Early Career Researcher Award from the Australian Research Council.
</span></em></p>Believe it or not, I have studied the hairy legs of spiders for years and can give you some definitive answers on this.Jonas Wolff, Research Fellow in the Department of Biological Sciences, Macquarie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1046672018-10-18T10:33:15Z2018-10-18T10:33:15ZSpiders scare me, but I also find them fascinating – and they help with my art<p>Eight schools in London have <a href="https://www.standard.co.uk/news/london/ninth-london-school-in-newham-closed-due-to-venomous-false-widow-spider-infestation-a3959706.html">closed this month</a> because of an infestation of spiders. The schools reported that they were concerned for the children’s well-being so they sent their pupils home – in one case for a whole month. It’s spider season again, when males are <a href="https://www.coventrytelegraph.net/news/coventry-news/how-to-get-rid-spiders-15137430">looking for females</a>, spiders are at their largest and their webs seem to fill every corner and crisscross every path. </p>
<p>Each year, just as predictably, comes the panic. This is a busy, and frustrating, time for arachnologists – who try to calm people’s fears with logic. These spiders <a href="https://www.theguardian.com/environment/shortcuts/2014/sep/23/hairy-scary-lethal-hunters-how-dangerous-household-spiders">will not kill you</a>, they say, the most they will do is give you a bite if you touch them, which will be no more painful than a bee sting. Yet in spite of these facts, the fear remains. Some animals, it seems, are simply born bad. The only logical response is to run away or kill them before they kill you. </p>
<p>As an artist, I became interested in spiders because, like me, they make things.
I have collected their silk, watched their courtship rituals and even invited one to join me in a duet – I serenaded a garden spider and recorded the vibrations of its web as it plucked the threads in response. Yet I still feel a lurch of panic when I hold one. My palms sweat and I can feel my heart rate increase.</p>
<p>But if we want to take environmental conservation seriously, we cannot pick only the animals that we find attractive. We have to find ways of living with animals that make us feel uncomfortable. Instead of running away or destroying them, we can choose a third option: get curious. Where do these animals live? How do they communicate? What do they make?</p>
<p>I started collecting spider webs when I was living in a dusty basement as a student 15 years ago. I teased apart the individual strands of silk and wove them into drawings and sculptures – a very time-consuming activity. <a href="https://www.sciencedirect.com/science/article/pii/S0003347209004941">Orb weaving spiders</a>, such as garden spiders, are able to produce seven different types of silk, each with different properties. Some are dry, strong and <a href="https://www.sciencedaily.com/releases/2013/01/130128104741.htm">famously tougher than steel</a>, while others form the sticky capture spiral of a web. </p>
<h2>Surfing the web</h2>
<p>The versatility of spider silk has made it an attractive and useful material to humans for hundreds of years. The oldest use of spider webs is <a href="https://www.ncbi.nlm.nih.gov/pubmed/30012067">as a wound dressing</a>. Spider webs are close to hand on the battlefield and they also have antibacterial properties that help us to heal and resist infection. <a href="https://www.pressetext.com/news/20030214021">Recent research</a> into artificial spider silk is expanding this medical potential by using silk to heal damaged tendons. It seems that our cells get on particularly well with spider silk proteins, not only do we not reject them, we actually stick to them. In the future we might all be part Spider Man or Woman. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/241089/original/file-20181017-41129-2dbfla.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/241089/original/file-20181017-41129-2dbfla.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=367&fit=crop&dpr=1 600w, https://images.theconversation.com/files/241089/original/file-20181017-41129-2dbfla.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=367&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/241089/original/file-20181017-41129-2dbfla.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=367&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/241089/original/file-20181017-41129-2dbfla.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=461&fit=crop&dpr=1 754w, https://images.theconversation.com/files/241089/original/file-20181017-41129-2dbfla.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=461&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/241089/original/file-20181017-41129-2dbfla.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=461&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Pholcidae – or Daddy Long-legs spider: the cannibal in the room.</span>
<span class="attribution"><span class="source">nelic via Shutterstock</span></span>
</figcaption>
</figure>
<p>Spiders have also played a central role in mapping the skies, measuring time and even fighting wars. From the early 19th century to the 1950s, spider silk was <a href="http://adsabs.harvard.edu/full/1992JATSo...1...10T">used to create</a> reticules and cross-hairs in telescopes, optical instruments and gun sights – during World War II, there was a surge in people collecting spider silk to sell to gun makers. One of the most successful was a Californian woman, <a href="http://adsabs.harvard.edu/full/1992JATSo...1...10T">Nan Songer</a>, who filled her sun room with black widow spiders. She described them as “docile as old milk cows”. </p>
<p>One of the most beautiful sights at this time of year is the glint of autumn light on spider webs. It is this magical appearance that has inspired people to attempt to weave clothes from spider webs. The problem is you need a lot of dry silk to make anything substantial, and spiders are resistant to commercial farming – they have a tendency to eat each other. </p>
<p>Perhaps an easier approach is used by the <a href="https://www.ancient-origins.net/artifacts-other-artifacts/museum-mix-creates-sticky-mess-spider-web-masks-did-not-suffocate-widows-021666">people of Malakula</a>, an island in the South Pacific archipelago of Vanuatu. Early in the morning, the men of the villages collect spider webs from trees using a bamboo frame. The webs stick together like felt fabric, and they use this to create masks, spiritual headdresses and even entire tunics. In Malakula, spiders are venerated rather than feared or destroyed. They reflect the cycle of life; every night many species of spider eat their webs and reuse this energy to weave a new web in the morning.</p>
<h2>Spider spotting</h2>
<p>Halloween is coming up, a celebration of all things fearful and I’d like to propose an activity. As evening falls and trick-or-treating begins, take a torch and go spider spotting. There are around 600 species of spider in the UK, and 35,000 in the world, so you can’t go far without spotting one – but here are a few of my favourites.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/240825/original/file-20181016-165924-1109gxr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/240825/original/file-20181016-165924-1109gxr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=446&fit=crop&dpr=1 600w, https://images.theconversation.com/files/240825/original/file-20181016-165924-1109gxr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=446&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/240825/original/file-20181016-165924-1109gxr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=446&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/240825/original/file-20181016-165924-1109gxr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=561&fit=crop&dpr=1 754w, https://images.theconversation.com/files/240825/original/file-20181016-165924-1109gxr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=561&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/240825/original/file-20181016-165924-1109gxr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=561&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Tegenaria domestica or the common household spider.</span>
<span class="attribution"><span class="source">John A. Anderson via Shutterstock</span></span>
</figcaption>
</figure>
<p>Starting in the bathroom is <em>Tegenaria domestica</em>, the house spider. At this time of year, these hairy brown creatures are probably males pausing for a drink of water while they search for females. On your way out of the house, look up to the corners of the ceiling where the <em>Pholcidae</em> – or Daddy Long-legs – live. These are the ones to encourage if you want to keep flies and other spiders at bay: they are keen cannibals. </p>
<p>Outside, head to any railings or fences. Here you will find two types of orb web: a classic Halloween symbol. If there’s a pizza slice cut out from the web, then it has been made by a Zygiella spider. But if it’s a complete web then it’s probably made my favourite of all spiders: <em>Araneus diadematus</em>, the garden spider and the species whose silk was most often used in <a href="http://britishspiders.org.uk/wiki2015/index.php?title=Are_Spiders_Useful">optical instruments</a>. It is largely thanks to this animal that we have accurate measurements of time and the land. </p>
<p>Finding out about spiders, and other unwelcome creatures, helps to lessen our fear. But it also enriches our world, by revealing our dependency on the extraordinary lives of others.</p><img src="https://counter.theconversation.com/content/104667/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Eleanor Morgan does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Autumn is spider season. It’s worth getting to know more about our eight-legged friends.Eleanor Morgan, Lecturer in Fine Art, Loughborough UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/817812017-08-09T09:44:54Z2017-08-09T09:44:54ZWhy abseiling spiders don’t spin out of control – new research<figure><img src="https://images.theconversation.com/files/181223/original/file-20170807-25504-1qi4o05.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/teteroon/15370193945/">Tobias Wrzal / Flickr</a></span></figcaption></figure><p>Seeing an abseiling spider descend gracefully using its dragline silk instead of spinning unpredictably and uncontrollably, led us to try and understand the science behind it. </p>
<p>Spiders use dragline silk for the outer rim and spokes of spider webs, as well as using it as a lifeline when dropping to the ground. This is the <a href="https://link.springer.com/chapter/10.1007/978-3-319-03125-5_13">strongest of the silks</a> produced by spiders, as it must support their entire weight. It is known to have <a href="http://www.chm.bris.ac.uk/motm/spider/page2.htm">extraordinary properties</a>, and is stronger than steel by weight. Spiders manufacture it at room temperature from simple sustainable materials so that it has no detrimental environmental impact. </p>
<p>But spiders dangling from a dragline silk are also rotationally stable, which is very different to loads suspended from a single, manmade rope – whether a natural rope like hemp, or a steel cable.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/181221/original/file-20170807-4030-cyt7mp.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/181221/original/file-20170807-4030-cyt7mp.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=348&fit=crop&dpr=1 600w, https://images.theconversation.com/files/181221/original/file-20170807-4030-cyt7mp.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=348&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/181221/original/file-20170807-4030-cyt7mp.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=348&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/181221/original/file-20170807-4030-cyt7mp.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=437&fit=crop&dpr=1 754w, https://images.theconversation.com/files/181221/original/file-20170807-4030-cyt7mp.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=437&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/181221/original/file-20170807-4030-cyt7mp.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=437&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Torsion happens when we twist an object.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Twisted_bar.png">Orion 8</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Torsion, or the act of twisting, is known as the most sensitive way to study the mechanical properties of materials. Henry Cavendish used <a href="http://www.colorado.edu/physics/phys1140/phys1140_sm98/Experiments/M4/M4.html">a torsion pendulum</a> in the 1700s to detect the gravitational attraction between metal balls in the laboratory. His experiment was known as <a href="http://www.physicsclassroom.com/class/circles/Lesson-3/Cavendish-and-the-Value-of-G">“weighing the Earth”</a>, because it measured Newton’s universal gravitational constant “G”. Charles-Augustin de Coulomb also used it <a href="http://ffden-2.phys.uaf.edu/104_2012_web_projects/cicely_shankle/Page%202%20-%20Coulomb's%20Experiment.html">to establish his law of electrostatic attraction</a>.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/T_GtrM-5AJo?wmode=transparent&start=8" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>Our research, initiated at Huazhong University of Science and Technology (HUST) and now continuing at Queen Mary University of London, developed an improved torsion pendulum based on image processing. By using this method, the back and forth oscillations of the pendulum can be recorded, and the twist angles can be found by analysing the image. We used this improved method to look at the <a href="http://aip.scitation.org/doi/10.1063/1.4990676">how spider silk responds to torsion</a>. </p>
<h2>Testing spider silk</h2>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/181226/original/file-20170807-25539-14orxfm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/181226/original/file-20170807-25539-14orxfm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/181226/original/file-20170807-25539-14orxfm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/181226/original/file-20170807-25539-14orxfm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/181226/original/file-20170807-25539-14orxfm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/181226/original/file-20170807-25539-14orxfm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/181226/original/file-20170807-25539-14orxfm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Golden orb weaver spider (Nephila edulis).</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/jean_hort/35213899592/">Jean and Fred / Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>We collected dragline silks from two species of golden silk orb weavers, <em>Nephila edulis</em> and <em>Nephila pilipes</em>, raised in the lab. We hung the dragline silk inside a cylinder – using two washers at the end to mimic the weight of a spider. We twisted the strands using a rotating turntable and released them, and recorded the oscillations with a video camera.</p>
<p>When Kevlar fibre, metal wires, and other conventional fibres are given a twist and released, they spin or oscillate around their initial resting point, this can be seen in the video above. What was staggering and unusual about spider silk, was that, for all initial twists, the silk oscillated around a position that was different from its original resting point. </p>
<p>That means that the silk is “yielding” when it is first deformed. All materials – rubber, steel, stone, modelling clay – deform under load, but at first spring back to their initial shape when the load is removed. This is called elasticity. At higher loads, very small for modelling clay and very high for steel, they yield or give, and remain permanently deformed. This is plasticity. The spider silk is both partially plastic and partially elastic right from the very first small deformation. No normal material behaves in this way, and it is very hard to explain how a material can do so.</p>
<p>The yielding dissipates the majority of the energy stored in the twist and in doing so reduces the size of the oscillations following it. Otherwise these oscillations would send a spider spinning on the bottom of its silk. The remaining energy could be dissipated by air resistance, or by friction in the molecular structure of the silk but we are not sure yet. For other conventional fibres, the oscillations die away mainly due to air resistance. </p>
<h2>On a molecular level</h2>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/181359/original/file-20170808-22975-1bco0rl.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/181359/original/file-20170808-22975-1bco0rl.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=829&fit=crop&dpr=1 600w, https://images.theconversation.com/files/181359/original/file-20170808-22975-1bco0rl.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=829&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/181359/original/file-20170808-22975-1bco0rl.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=829&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/181359/original/file-20170808-22975-1bco0rl.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1041&fit=crop&dpr=1 754w, https://images.theconversation.com/files/181359/original/file-20170808-22975-1bco0rl.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1041&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/181359/original/file-20170808-22975-1bco0rl.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1041&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Spider silk fibril, with amorphous chains (black) and crystalline sheets (yellow)</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Spider_silk_microscopic_structure.png">Kebes</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>A dragline silk is composed of lots of tiny “fibrils”, and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2658765/">each fibril contains proteins</a> that form a combination of <a href="http://www.chm.bris.ac.uk/motm/spider/page3.htm">“amorphous chains” and “crystalline sheets”</a>.</p>
<p>Amorphous chains are loosely linked together with hydrogen bonds, and have no rigid shape. Crystalline sheets on the other hands, have a very defined structure. </p>
<p>We speculated that, under torsion, the amorphous chains, which are held together by weaker bonds, can be easily deformed. That deformation, together with friction between fibrils, can quickly dissipate the energy applied. Meanwhile, the crystalline sheets can recover their original shapes after being deformed, so they maintain the shape of the silk.</p>
<p>A better understanding of how dragline silk resists spinning may eventually lead to the development of biomimetic fibres with the same properties. This would lend itself to improvements in a huge range of areas, like helicopter rescue ladders and parachute cords. Much work remains to be done, but the secrets of spider silk are beginning to be unravelled.</p><img src="https://counter.theconversation.com/content/81781/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>If we could mimic spider silk, it could revolutionise the fibres we use on a daily basis.David J Dunstan, Professor of Experimental Physics, Queen Mary University of LondonDabiao Liu, Marie Curie Research Fellow, Queen Mary University of LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/710032017-02-01T19:05:20Z2017-02-01T19:05:20ZWhy we can’t spin a silken yarn as strong as a spider can<figure><img src="https://images.theconversation.com/files/154696/original/image-20170130-7693-11h1u2c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">If it's good enough for a spider, why can't we make such strong silk?</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/chillmimi/8432405400/">Flickr/Petra Bensted</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Silk is a high performance protein-baed fibre that is naturally produced by invertebrates. The most well-known is the domesticated silk moth (<a href="https://www.britannica.com/animal/silkworm-moth"><em>Bombyx mori</em></a>), whose silk has been used in fabrics for more than 4,000 years.</p>
<p>Spiders also produce silk. The dragline silk – used for building the framework of webs and safety lines for the spider – has strength greater than steel and toughness greater than <a href="http://www.dupont.com.au/products-and-services/fabrics-fibers-nonwovens/fibers/brands/kevlar.html">Kevlar</a>. </p>
<p>What is more impressive is that it is produced within aqueous solutions at room temperature, and is highly biocompatible – meaning it’s non-toxic – and bacterial resistant.</p>
<p>If we could tap in to the secrets of this material it could herald a revolution in manufacturing. A swathe of high performance materials could potentially be produced, such as ultra-tough ropes and cables, light-weight safety uniforms, super-strong and light cases, binding sutures and other medicinal materials.</p>
<p>But unlike silkworms, harvesting silk directly from spiders is not a commercially viable option. Spiders require vast amounts of space for their webs, individual spiders do not produce high quantities of silk, and spiders tend to eat each other.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/155102/original/image-20170201-12669-rrbimc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/155102/original/image-20170201-12669-rrbimc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/155102/original/image-20170201-12669-rrbimc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/155102/original/image-20170201-12669-rrbimc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/155102/original/image-20170201-12669-rrbimc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/155102/original/image-20170201-12669-rrbimc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/155102/original/image-20170201-12669-rrbimc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/155102/original/image-20170201-12669-rrbimc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Spiders use their silk to wrap up their prey.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/amylloyd/4983475214/">Flickr/Amy Felce</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
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<h2>Synthetic spider silk</h2>
<p>There have been some recent advances in our understanding of dragline silk protein structures. So why has commercial scale genetic engineering of a material that performs as well as natural spider silk <a href="http://pubs.rsc.org/en/Content/ArticleLanding/2011/SM/C1SM05812F#!divAbstract">proven exceptionally difficult</a>?</p>
<p>One reason is that the silk proteins created using genetic engineering and recombinant technologies have not been based on full-length spider silk gene sequences. </p>
<p>Also, an incomplete understanding of the natural spinning processes, and the influences of the internal and external environment over silk properties, <a href="http://www.annualreviews.org/doi/abs/10.1146/annurev-ento-031616-035615">appears to present a significant challenge</a>.</p>
<p>The best way forward in the quest for any large scale <a href="http://science.sciencemag.org/content/329/5991/528.full">production of spider silk-like materials</a> is through the processes of genetic engineering and biomimetics – mimicing the spider’s biological process. But again, significant obstacles still exist.</p>
<h2>How does a spider do it?</h2>
<p>Dragline silk is manufactured by spiders within the a gland called major ampullate gland. This gland is the <a href="http://pubs.acs.org/doi/abs/10.1021/bm400898t">longest and most complex of all the silk glands</a> of spiders, so much so that it can be subdivided visibly into a tail, sac and duct region.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/155096/original/image-20170201-12649-s2jh18.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/155096/original/image-20170201-12649-s2jh18.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/155096/original/image-20170201-12649-s2jh18.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=138&fit=crop&dpr=1 600w, https://images.theconversation.com/files/155096/original/image-20170201-12649-s2jh18.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=138&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/155096/original/image-20170201-12649-s2jh18.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=138&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/155096/original/image-20170201-12649-s2jh18.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=174&fit=crop&dpr=1 754w, https://images.theconversation.com/files/155096/original/image-20170201-12649-s2jh18.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=174&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/155096/original/image-20170201-12649-s2jh18.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=174&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Macroscopic image of a spider silk gland showing in (a) the anterior silk gland (ASG), funnel, middle silk gland (MSG) and posterior silk gland (PSG) and in (b) a major ampullate gland with duct, funnel, sac and tail.</span>
<span class="attribution"><a class="source" href="http://www.mdpi.com/1422-0067/17/8/1290">Marlene Andersson, Jan Johansson and Anna Rising. Silk Spinning in Silkworms and Spiders. International Journal of Molecular Sciences. 2016; 17(8):1290.</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
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<p>The proteins that make up the silk – known as spidroins – are secreted into the tail and stored in the sac as a concentrated liquid crystalline solution, called dope.</p>
<p>The dope is drawn through the duct during the process of fibre spinning where changes in salt concentration and pH induce the spidroins to form chains, and aggregate and fold into various secondary structures.</p>
<p>The dope forms a gel and flows further through the duct, which narrows considerably. This narrowing of the duct generates shear stress on the dope, which results in further folding and structural modification of the proteins.</p>
<p>Once pulled through the spinning valve by the spider (no, it is not squirted like Spiderman) the dope dehydrates and a solid fibre forms.</p>
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<h2>Efforts to mimic spider silk</h2>
<p>Developing synthetic fibres by mimicing the spider’s biological spinning approach involves three steps:</p>
<ol>
<li><p>The creation of the proteins that give spider silk its properties,</p></li>
<li><p>sequential chemical and physical treatment of the proteins under specific conditions to promote aggregation and folding at precise moments, and</p></li>
<li><p>spinning and drawing the fibres at controlled speed, preferably using water as a solvent.</p></li>
</ol>
<p>Limitations have been encountered by researchers at each of these stages which have compromised the properties of the fibre produced.</p>
<p>Synthetic silk spinning first needs a spinning dope. Three sources of dope are used for artificial silk spinning: native, recombined and genetically modified dopes. </p>
<p>Native dope is preferred but can only be obtained either directly from the major ampullate gland of sacrificed spiders or from fibres dissolved in caustic solvents.</p>
<p>It is extremely difficult, almost impossible, to obtain sufficient quantities of native dope for commercial scale silk synthesis.</p>
<figure>
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<h2>How to make dope</h2>
<p>An alternative is to derive a spinning dope by recombinant protein expression. This means inserting spider silk genes into bacteria and getting the bacteria to express the proteins.</p>
<p>The problem here is that the full-length sequences of spidroin-encoding genes are only known for a few species.</p>
<p>Attaining full length spider silk proteins by recombinant expression is difficult because the silk proteins are exceptionally large and so difficult for the bacteria to secrete, and for researchers to isolate and purify.</p>
<p>A limited range of recombinant silk proteins can thus be produced. It is now known that other encoding genes also influence the <a href="http://pubs.acs.org/doi/abs/10.1021/acs.jproteome.5b00353">structure and function of natural spider silks</a>. </p>
<p>Clearly, we do not yet know enough about the expression and function of the silk proteins and the role of other genes, and how they interact with the environment, to exploit recombinant technologies for making artificial silk.</p>
<figure class="align-center zoomable">
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<figcaption>
<span class="caption">Easier for a spider to spin a beautiful web than it is to create a synthetic silk.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/dmills727/2214997534/">Flickr/Douglas Mills</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>Spinning dopes can be created by genetically modifying proteins secreted by bacteria such as <a href="http://www.sciencedirect.com/science/article/pii/S1389035200000088"><em>E. coli</em></a>, yeasts, plants such as <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1467-7652.2004.00087.x/full">tobacco</a>, or in animals. For example, silk proteins have been synthesised using <a href="http://science.sciencemag.org/content/295/5554/472">hamster liver cells</a> and mammary cells from goats.</p>
<p>But this approach produces dopes that contain silk-like proteins of significantly lower molecular weights than native spidroins. These proteins need special treatment to induce the individual chains to join up.</p>
<p>The <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0105325">expression of spider silk spidroins in silkworms</a> has recently been done and shows potential for producing higher molecular weight genetically modified proteins, but the fibres produced are not as tough as spider silk fibres.</p>
<h2>Problems with protein treatments</h2>
<p>It seems crucial that the chemical and physical treatments of the dope, however it is attained, must closely mimic the natural spinning processes.</p>
<p>But our knowledge is poor of the natural processes occurring between protein secretion and spinning, and how they can cause variations in silk performance across environments.</p>
<p>We know that a combination of changes in water content, salt concentration, pH and shear stresses act on the dope within the silk gland, and that these processes induce protein structural rearrangements in the spun fibres. </p>
<p>But an understanding of how these induce the changes in silk properties is still unknown and <a href="http://www.spidersilkresearch.com.au/">our lab at UNSW</a> is working on this problem. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/155117/original/image-20170201-12675-jzpgtk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/155117/original/image-20170201-12675-jzpgtk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/155117/original/image-20170201-12675-jzpgtk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/155117/original/image-20170201-12675-jzpgtk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/155117/original/image-20170201-12675-jzpgtk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/155117/original/image-20170201-12675-jzpgtk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/155117/original/image-20170201-12675-jzpgtk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/155117/original/image-20170201-12675-jzpgtk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">More research is needed before commercial production of spider-like silk is a go.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/11797866@N05/6013315671/">Flickr/Tonya</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<p>There have been reports of silks being produced with <a href="https://cen.acs.org/articles/92/i9/Spider-Silk-Poised-Commercial-Entry.html">material properties approaching those of spider silk</a>. But again, the gaps in our understanding of the biology and physical chemistry of silk spinning by spiders still limits the performance of the synthetic silks.</p>
<p>Methods presently used for spinning artificial silk fibres include electrospinning, mechanical spinning, microfluidic devices and solvent injection. </p>
<p>Technically, none of the methods mimics the natural silk spinning processes of spiders. Rather they are tried and tested modifications of established fibre spinning protocols. </p>
<p>Nevertheless, researchers have made considerable progress in the spinning of high quality artificial silks from recombinant proteins using such methods. Recently, a team from Sweden produced synthetic silk fibres with tensile strengths that <a href="http://www.nature.com/nchembio/journal/vaop/ncurrent/full/nchembio.2269.html?WT.feed_name=subjects_biotechnology">neared that of natural dragline silk</a>.</p>
<p>So while there have been some exciting advances, a lot of obstacles remain before we can seriously consider any commercial manufacture of artificial spider silk.</p><img src="https://counter.theconversation.com/content/71003/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Sean Blamires receives funding from Australian Research Council.</span></em></p>Spider silk is strong stuff and could be used to manufacture ultra tough ropes and cables, and better sutures in medicine. If only we could find a way to make the stuff.Sean Blamires, Senior Lecturer in Evolutionary Biology, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.