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The Scientist » The Nutshell
Zeroing in on the Gay Gene
The largest study yet of the genetic roots of homosexuality links sexual preference in men to two regions of the genome.
By Bob Grant | November 19, 2014
ALEKSANDAR STOJKOVIC/SHUTTERSTOCK
At least in men, homosexuality may be a function of genetics, according to a study of more than 400 pairs of gay brothers. The research, published yesterday (November 18) in Psychological Medicine, confirms the role of a stretch of the X chromosome in determining sexual preference in men, a finding first suggested more than 20 years ago. Geneticist Dean Hamer, scientist emeritus at the National Institutes of Health, published a study in 1993 that proposed that Xq28, a region of the X chromosome, might play a role in determining whether a man was gay. When you first find something out of the entire genome, youre always wondering if it was just by chance, Hamer told Science of the new study, adding that the research clarifies the matter absolutely.
Hamer, who recently wrote an opinion piece in The Scientist about the responsibilities of researchers who study sexual orientation, only studied 38 pairs of brothers in his 1993 study, but he told New Scientist that he sees the new paper as confirmation of his work. Twenty years is a long time to wait for validation, but now its clear the original results were right, he said. Its very nice to see it confirmed.
But as was the case in 1993, not all researchers are convinced that science is homing in on the biological roots of sexual preference. Even the senior author on the Psychological Medicine paper, Northwestern University psychologist Michael Bailey, had his doubts. I thought that [Hamer] did a fine but small study, he told Science. If I had to bet, I would have bet against our being able to replicate it.
But when Bailey, who also wrote an opinion piece for The Scientist on the search for the biological roots of homosexuality, and his colleagues analyzed single nucleotide polymorphisms (SNPs) in the DNA of the brother pairs, they found five SNPs that were commonly shared by all the gay men. And those SNPs clustered in the Xq28 region on the X chromosome and in the 8q12 region of chromosome 8.
Bailey and his colleagues are now working on a genome-wide association study to confirm the results of their genetic linkage research. This analysis, which will include DNA samples from more than 1,000 additional gay men, may narrow the search for genetic signals for homosexuality down to individual genes. It looks promising for there being genes in both of these regions, Bailey told Science. But until somebody finds a gene, we dont know.
no propaganda please wrote:
It is still just that there may be a link between sexual preference and genetic influence, nothing definite. It would have more validity if the twins were separated at birth so no environment was not involved and included several thousand heterosexual identical twins where NO STRETCH in the genetic linkage was present. There is probably a connection from the standpoint that certain personalities are more likely to be same sex attracted such as sensitive, fragile temperaments, or boys who have been chronically sick as little children, which might have a genetic linkage, are somewhat more likely to develop same sex attraction, but it may be because of the problem developing a truly masculine identity when you can't play and roughouse with other boys but must be sedate more like a girl. What you should be concerned about is if there is an identifiable gene and the abortion rate for those babies is very high.
It is still just that there may be a link between ... (
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