Medical researchers at the European Molecular Biology Laboratory in Heidelberg, Germany, altered a single gene in female mice. The mice did not change anatomically, but their ovaries began producing testosterone:
The scientists noted that their research contradicts the claim that female is the default gender among embryos without a male sex-determining gene.
Link via Popular Science | Photo: US Department of Energy
The study was carried out on mice but the implications are relevant to humans, the scientists said. By switching off a gene called FoxL2, which exists in all mammals, the ovary cells of adult female mice developed spontaneously into the fully developed, testosterone-producing cells found in male testes, although they could not produce sperm.
"We take it for granted that we maintain the sex we are born with, including whether we have testes or ovaries," said Robin Lovell-Badge, from the Medical Research Council's National Institute of Medical Research in north London, who was part of the international team led by the European Molecular Biology Laboratory in Heidelberg.
The scientists noted that their research contradicts the claim that female is the default gender among embryos without a male sex-determining gene.
Link via Popular Science | Photo: US Department of Energy
I'm not exactly sure how it would contradict that claim, (if I remember correctly, the claim is only that the egg only contains X chromosomes, because everyone has them) but I guess I'd have to read the research. I'd think it'd be pretty easy to determine which chromosomes exist in eggs, though, since they are visible under intense magnification.
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