Ovary-promoting, female sex determining factor found

[Jessica]

http://www.the-scientist.com/news/display/25087/

A team of Italian researchers has identified a new sex-determination gene, according to a report in Nature Genetics. Genetic analysis has implicated R-spondin1, a member of a relatively new class of mitogens, as an ovary-promoting factor, the loss of which leads to complete sex reversal - that is, to XX males.

This challenges the notion that female is the 'default' sex in nature.

[angelsgirl]

That's really very interesting.  I'm glad I'm studying biology this semester, I could make sense out of some of that!