Dr Peter Ellis is a Lecturer in Molecular Genetics and Reproduction at the University of Kent. His laboratory investigates the molecular biology of reproduction, the conflicting roles played by sex-linked genes in regulating this process, and the relationship between DNA damage repair mechanisms and the checkpoints governing meiotic progression. Key findings from his work to date include the identification of novel genes on the mouse Y chromosome that affect sperm head shape and fertility; the discovery of a genomic conflict or arms race between the X and Y chromosomes in mice as they compete to influence offspring sex ratio, which in turn has dramatically affected the structural and functional content of both chromosomes; and the identification of mechanisms regulating meiotic and post-meiotic transcriptional silencing of the sex chromosomes.
MA in Medical Sciences, University of Cambridge (1999)
PhD, University of Cambridge (2003)
PGCHE and FHEA (2016)
Current Research Projects:
1) DNA damage repair in reproduction and cancer
Meiotic germ cells and cancer cells share a number of unusual features including high rates of cell division, the ability to tolerate high numbers of DNA strand breaks and rearrange the genome without undergoing apoptosis, and (in oocytes) a lowered stringency spindle assembly checkpoint that permits cell division even in the presence of unattached kinetochores. Dr Ellis studies how cancer-testis antigens (genes expressed only in the testis and cancer) regulate these processes.
2) The role of Yq-linked genes in fertility and offspring sex ratio
Mouse chromosome arm Yq is highly ampliconic, with Yq-linked genes being present in up to ~600 copies. Deletions on Yq (Yqdel) titrate the copy number level of the ampliconic genes on this chromosome arm. Yqdel males show a dose-dependent fertility phenotype, with smaller deletions leading to mild teratozoospermia and larger deletions leading to severe teratozoospermia and infertility. In the fertile males with smaller deletions, there is an offspring sex ratio skew in favour of females. Since X and Yqdel-bearing sperm are produced in equal numbers, the skew must be due to differential fertilising capacity between X-bearing and Yqdel-bearing sperm. Dr Ellis’ work in this model system is aimed at clarifying the physiological basis of the sex ratio skew, and understanding the molecular functions of the Yq-encoded genes that regulate sex ratio.
3) Mechanisms of non-Mendelian inheritance
The earliest genetic concept taught in schools is Mendel’s First Law of Segregation: that you have two copies of each gene, and an equal chance of passing on either of the copies. Dr Ellis studies how and why Mendel’s Law breaks down, allowing meiotic drive genes – so-called genetic outlaws – to bias the reproductive lottery and promote their own inheritance. Key questions to resolve are how many driving genes there are, where they are in the genome, and how they work.