In most mammals, that the embryo develops as ‘female’ unless a specific Y-chromosome gene called Sry is present to trigger ‘male’ development has been known for a while now. But new research by Prof. Peter Koopman (part of the team that originally discovered this role of the Sry gene) and his team has shown that there is more to it than that.
While Sry is indeed responsible for switching on the ‘maleness’ genes, it turns out that having it is not, on its own, enough to drive ‘male’ embryonic development. While studying DNA packaging in embryos the researchers observed that, for Sry to be expressed, the DNA first needed to be unwound by an enzyme called Jmjd1a – without it (as was observed in a group of mice), the embryos will develop as female whether or not they have a Y chromosome.
Prof. Koopman and his team hope that this latest study could help lead to a better understanding of the cause behind certain intersex conditions.
Press release: http://bit.ly/195dAWY
Image: 9-Week Human Embryo from Ectopic Pregnancy. euthman/Flickr