What do the new ‘gay gen’ tell about sexual orientatn? | New Scientist

Contents:

• THERE IS NO ‘GAY GENE.’ THERE IS NO ‘STRAIGHT GENE.’ SEXUALY IS JT PLEX, STUDY NFIRMS
• GAY GEICSMOST OF BELIEVE THAT WE WERE BORN THAT WAY, BUT IS SEXUAL ORIENTATN OUR DNA? JV CHAMARY GO SEARCH OF THE GAY GENEJV CHAMARYPUBLISHED: MAY 31, 2009 AT 11:00 PMGAY GEICS
• THERE’S (STILL) NO GAY GENE
• THE LIFE OF THE GAY GENE: OM HYPOTHETIL GEIC MARKER TO SOCIAL REALY
• WHAT DO THE NEW ‘GAY GEN’ TELL ABOUT SEXUAL ORIENTATN?
• THE REAL STORY ON GAY GEN
• SEARCH FOR 'GAY GEN' COM UP SHORT IN LARGE NEW STUDY
• MANY GEN INFLUENCE SAME-SEX SEXUALY, NOT A SGLE ‘GAY GENE’

THERE IS NO ‘GAY GENE.’ THERE IS NO ‘STRAIGHT GENE.’ SEXUALY IS JT PLEX, STUDY NFIRMS

However, blogists have documented homosexual behavr more than 450 speci, argug that same-sex behavr is not an unnatural choice, and may fact play a val role wh populatns. The 2019 study is the latt a hunt for “gay gen” that began 1993, when Dean Hamer lked male homosexualy to a sectn of the X chromosome. So-lled genome-wi associatn studi intified a gene lled SLITRK6, which is active a bra regn lled the diencephalon that differs size between people who are homosexual or heterosexual.

GAY GEICSMOST OF BELIEVE THAT WE WERE BORN THAT WAY, BUT IS SEXUAL ORIENTATN OUR DNA? JV CHAMARY GO SEARCH OF THE GAY GENEJV CHAMARYPUBLISHED: MAY 31, 2009 AT 11:00 PMGAY GEICS

” For example, certa gen women help crease their fertily, but if the gen are exprsed a male, they predispose him toward homosexualy.

THERE’S (STILL) NO GAY GENE

While there is no sgle “gay gene, ” there is overwhelmg evince of a blogil basis for sexual orientatn that is programmed to the bra before birth based on a mix of geics and prenatal ndns, none of which the fet choos. It is worth keepg md that this study only vers some typ of sexualy — gay, lbian and cis-straight — but don’t offer many sights to genr inty. Humans have tried to unrstand human sexualy for centuri — and geics rearchers joed the ay the early 1990s after a seri of studi on tws suggted homosexualy ran fai.

“As a teenager tryg to unrstand myself and unrstand my sexualy, I looked at the ter for “the gay gene” and obvly me across Xq28, ” said Fah Sathirapongsasuti, a study -thor and senr scientist at 23andMe, which he joked once led him to believe he hered his gayns om his mother.

THE LIFE OF THE GAY GENE: OM HYPOTHETIL GEIC MARKER TO SOCIAL REALY

“We worried a lot about volunteer bias, ” said Bailey, whose rearch clus a wily publicized study on Xq28 and gay brothers om 2018. The rearchers had members of the same-sex muny review the study’s sign and language, and they adm that their termology and fns for gay, lbian and heterosexual do not reflect the full nature of the sexualy ntuum.

“[Our study] unrsr an important role for the environment shapg human sexual behavr and perhaps most importantly there is no sgle gay gene but rather the ntributn of many small geic effects sttered across the genome, ” Neale said. The search for ‘gay gen’ go back to 1993, when a US team led by Dr Dean Hamer scribed a regn of DNA loted on the X chromosome lled Xq28.

“Conservative, right-wg people hated bee they felt that was sayg that beg gay is like beg black, that was -born, that would somehow ‘exce’ gay people or give them more rights, ” says Hamer. “On the other hand, gay people hated too bee, at that time, there were fears that the disvery would be mised to abort gay babi and wipe gay people off the face of the Earth. Although the fears rema, recent years the search for ‘gay gen’ has bee more accepted by the gay muny, no small part bee a blogil explanatn wouldunrme arguments that beg gay is a social or liftyle choice.

WHAT DO THE NEW ‘GAY GEN’ TELL ABOUT SEXUAL ORIENTATN?

For stance, intil tw brothers (siblgs rived om the same fertilised egg) are more likely to both be gay than aternal tws (tws that velop om separate eggs).

Now chief of the gene stcture and regulatn sectn at the US Natnal Cancer Instute, his study revealed a cur pattern: gay men tend to have more gay uncl and gay male s on their mother’s si of the fay than on their father’s.

To track down the DNA regn lked to the gay tra, Hamer ed a technique lled ‘lkage mappg’, an approach that lets geicists fd a gene even when they don’t know what do or where ’s loted.

THE REAL STORY ON GAY GEN

Lkage mappg works bee close relativ like brothers share not only a particular tra, such as homosexualy, but also the gen unrlyg the tra. So, if you study many pairs of gay brothers and fd a DNA regn that’s the same more than 50 per cent of s, ’s likely to be lked to homosexualy. A subsequent study 1999 failed to replite Hamer’s rults and other rearchers are sceptil that Xq28 is lked to homosexualy at all.

SEARCH FOR 'GAY GEN' COM UP SHORT IN LARGE NEW STUDY

Asi om a few superficial differenc (among them penis and rg-fger length – both longer homosexuals), gay and straight men’s bodi appear the same. The exceptn is homosexual men’s bras, which show remarkable siari to the bras of heterosexual women, suggtg that sexual orientatn pends on the effect hormon have on the velopg bra.

In 1996 Blanchard and Profsor Tony Bogaert revealed a peculiar phenomenon: the more olr brothers a boy has, the greater their chanc of beg homosexual.

MANY GEN INFLUENCE SAME-SEX SEXUALY, NOT A SGLE ‘GAY GENE’

Blanchard believ that homosexualy is “100 per cent blogil”, and timat that the aternal birth orr effect acunts for 15-30 per cent of gay men the populatn. Not only did he replite Blanchard’s birth orr effect, he also tected herance of homosexualy on the mother’s si, supportg Hamer’s ia of a gay gene on chromosome X. Natural selectn oppos anythg that might e even a small rctn the number of offsprg you produce, so a gay tra would soon disappear om the gene pool.

After Camper Ciani scribed the observed patterns pedigre of homosexualy – the effects of maternal herance and birth orr – his dghter suggted that he re-check his data to see if the female relativ of gay men had more children on the mother’s si. “Mothers and nts on the maternal le of homosexuals had around one-fifth to one-fourth more kids than the heterosexual parison, and also than the paternal le. In this stance, the ‘gay gen’ don’t exist to make men homosexual, stead they’re a nsequence of ‘fertily factors’ that help women reproduce.

While they may nfirm the ia that homosexualy has a blogil basis, many people fear that the rults uld be ed to discrimate agast gay people. “People we talked to at gay pri ftivals have signer-baby kd of worri – a geic tt employed a pre-natal way, or for employment and surance discrimatn, maybe the ary too. There is no one gene for beg gay, and though gen seem to play a role termg sexual orientatn and same-sex behavr, ’s small, plex, and anythg but termistic.