What decides the development of testes or ovaries?
In 1990, researchers at the Imperial Cancer Research Fund and the National Institute for Medical Research together tracked down a gene that plays a pivotal role in the initiation of sex development.
Though scientists knew that embryos with a Y chromosome usually went on to develop testes and then other male organs, no one knew what sparked this process until Peter Goodfellow and Robin Lovell-Badge identified a likely candidate gene, which they called SRY.
Robin and Peter made headline news by showing that if this Y chromosome gene was introduced into XX mouse embryos, which normally develop ovaries, they developed testes instead. In humans, the activity or absence of SRY during pregnancy has a similarly significant impact.
A XX mouse with the SRY gene (Photo: Medical Research Council / Science Photo Library)
The Imperial Cancer Research Fund and National Institute for Medical Research are now part of the Francis Crick Institute, where Robin still works.
Here, James Turner studies genes on the X and Y chromosomes, exploring their role in development, disease and infertility.