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Growing human embryos in the lab and why scientists just tweaked the rules – podcast

3D illustration of an early stage human embryo
Illustration of an early stage human embryo. nobeastsofierce via Shutterstock

In this week’s episode of The Conversation Weekly, as new scientific guidelines are released on embryo research and the use of stem cells, we talk to experts about what’s changed – including a recommendation to relax the 14-day time limit for human embryo research. And we hear about a wave of romantic comedy films emerging from South Africa that are re-imagining the city of Johannesburg.

It’s been five years since the last set of guidelines from the International Society for Stem Cell Research (ISSCR) were published. Since then, scientists have made significant developments in stem cell and embryo research – including the creation of human embryo models and the first human-monkey embryos.

Now, new ISSCR guidelines have just been published. One of the most significant shifts concerns what’s called the 14-day rule. This has prohibited researchers – by law in some countries, such as the UK – from growing human embryos in the lab for more than 14 days. The revised guidelines no longer strictly prohibit this, rather they recommend that a panel of experts should approve research proposals on a case-by-case basis. And they also call on countries to start national conversations about the issue and whether such research should be allowed.

The ISSCR guidelines are not international law, but their recommendations are used by countries around the world to guide their own national regulations and legislation. And also by countries that don’t have laws governing this kind of research using embryos and stem cells.

For this episode, we talk to Megan Munsie, deputy director for the Centre for Stem Cell Systems at the University of Melbourne and one of the scientists who sat on the panel that reviewed the guidelines. She tells us there have been advances that mean that we can now grow sperm-egg embryos for more than 14 days, “and the guideline is calling for consideration about whether we should”. She says that in a very small number of cases there may be justification for doing so.

Read more: New global guidelines for stem cell research aim to drive discussions, not lay down the law

The guidelines stress that doing research using human embryos should be a last resort – only turned to if there is no other way to get the same information. And this is where human embryo models come in. We speak to Jun Wu, assistant professor in molecular biology at the University of Texas Southwestern Medical Center, whose lab recently made a breakthrough by creating a human embryo model, called a blastoid, using human pluripotent stem cells. He explains how he did it and why this kind of research is so important to help understand what happens in the earliest stages of pregnancy, when the embryo implants into the womb lining. “This process of implantation is essentially a black box,” Wu says. “We don’t know much about it.”

And we speak to César Palacios-González senior research fellow in practical ethics at the Uehiro Centre for Practical Ethics at the University of Oxford, about some of the moral dilemmas that the 14-day rule and research using human embryos provoke. “Philosophers like myself love thinking about these things,” he told us. “The main ethical question that people have in mind is the moral value that human embryos have, and if actually we should even be carrying out this particular type of research.” He explains the arguments on both sides.

In our second story (at 25:20), we head to South Africa, where a wave of romantic comedies has hit the big screen in recent years. Many of these films are set in Johannesburg – a city that’s had a violent portrayal in film. Pier Paolo Frassinelli, professor of communication and media studies at the University of Johannesburg has just published new research looking at the way Black South African filmmakers are now portraying Joburg in a different light through these romcoms. “Even though the films try to present a certain image of upper-middle-class Johannesburg, the films cannot quite push away the tensions, the contradictions, the complexities of the city,” Frassinelli tells us.

Read more: South Africa's romcom revolution and how it reimagines Joburg

And Wale Fatade, commissioning editor at The Conversation in Lagos, Nigeria, gives us his recommended reading.

The Conversation Weekly is produced by Mend Mariwany and Gemma Ware, with sound design by Eloise Stevens. Our theme music is by Neeta Sarl. You can find us on Twitter @TC_Audio, on Instagram at theconversationdotcom. or via email on You can also sign up to The Conversation’s free daily email here.

A transcript of this episode will be available soon.

News clips in this episode are from ABC News Australia, AP News, Rififi Pictures Trailer: Tell me Sweet Something, Showmax, Trailer: Happiness is a Four Letter Word, Mrs Right Guy Official, Trailer: Mrs Right Guy, Sony Picture Entertainment: District 9 - Official Trailer and Movieclips Classic Trailers, Trailer: Jerusalema.

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