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IS THERE A 'GAY GENE'? REARCHERS THK SO
For the first time, rearchers have found associatns between homosexualy and markers attached to DNA that n be fluenced by environmental studi and fay tre provi strong evince that sexual orientatn is at least partly geic. When one intil tw is gay, there is about a 20% chance that the other will be as well1.
NEW THEORY: THE GAY TRA IS PASSED DOWN FROM PARENT TO CHILD
One of the bt characterized is the 'olr brother effect': the chance of a man beg gay creas by 33% for each olr brother he has2. The 'epi-marks' n be hered, but n also be altered by environmental factors such as smokg, and are not always shared by intil rearchers llected DNA sampl saliva om 37 pairs of intil tws which only one tw was gay, and 10 pairs which both were gay. By snng the tws’ epigenom, the rearchers found five epi-marks that were more mon among the gay men than their geilly intil straight brothers.
Ngun says that the rearchers want to replite the study a different group of tws and also terme whether the same marks are more mon gay men than straight men a large and diverse populatn. “We already know there is no 'gay gene', ” says William Rice, an evolutnary geicist at the Universy of California, Santa Barbara.
If there were, he says, would have turned up one of the massive studi that sn the whole genome for variants shared between gay people. The largt such study, led by Sanrs, looked at 409 pairs of gay brothers cludg some non-intil tws. The rearchers found that gay men shared siari two areas of the genome: the X chromosome and chromosome 83.