'Sexual Preference' Gene Turns Female Mice Off Male Advances
That's according to research out of South Korea, published this week in the journal BMC Genetics.
The gene, fucose mutarotase (FucM), is responsible for the release of an enzyme by the same name, and seems to cause developmental changes in brain regions that control reproductive behaviors.
The mice without the enzyme would refuse to let males mount them, and instead tried to copulate with other females.
Even though they weren't looking to get freaky with their male partners, forced procreation yielded pregnancy -- meaning that the females remained fertile despite the genetic tinkering.
"We speculate that these behavioral changes are likely to be related to a neuro-developmental change in pre-optic area of the female mutant brain, becoming similar to that of a normal male," Professor Chankyu Park, of the Korea Advanced Institute of Science and Technology, told UPI.
In particular, removing the gene exposes the brain to extra estrogen, which is responsible for masculinity in mice. In humans, testosterone does similar things.
So while other scientists are already noting that the precise hormonal mechanisms differ among humans, the finding does explain some of the neurological basis for sexual preference among mammals.
"Nevertheless, it is probably only a matter of time before molecular geneticists identify genes that influence sexual orientation in humans," Simon LeVay, an expert in human sexuality, told the New Scientist.