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
• WHAT DO THE NEW ‘GAY GEN’ TELL ABOUT SEXUAL ORIENTATN?
• 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
• WHY ARE PEOPLE GAY? GAY BY CHOICE OR IS BEG GAY GEIC?
• SCIENTISTS FD DNA DIFFERENC BETWEEN GAY MEN AND THEIR STRAIGHT TW BROTHERS
• NO ‘GAY GENE’: MASSIVE STUDY HOM ON GEIC BASIS OF HUMAN SEXUALY
• THERE’S NO ONE ‘GAY GENE,’ BUT GEICS ARE LKED TO SAME-SEX BEHAVR, NEW STUDY SAYS
• THERE’S (STILL) NO GAY GENE
• 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

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.

“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.

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

We have known for s that sexual orientatn is partly herable men, thanks to studi of fai which some people are straight and some people are gay.

In 1993, geic variatns a regn on the X chromosome men were lked to whether they were heterosexual or homosexual, and 1995, a regn on chromosome 8 was intified.

Grave’s disease is more mon gay than straight men, and some rearch suggts that gay men tend to be thner – which might possibly be a rult of thyroid overdrive. The latt fdgs open the prospect to intifyg the whole pathway of gen volved both homosexual and heterosexual orientatn, says Dean Hamer at the US Natnal Instut of Health, who led the study that ppoted chromosome X back 1993. Some people who have had sex wh a same-sex partner don’t nsir themselv gay and aren’t exclively attracted to people of the same sex, Bailey says.

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

Men the new study who said they have had same-sex partners, tend to be more exclively homosexual than women were, Ganna and lleagu found.

Bbank dataset, for example, younger people reported havg same-sex partners more often than olr people did, probably bee homosexual activy was illegal the Uned Kgdom until 1967. In the new study, the more exclively homosexual partners men had, the fewer children they had; up to 80 percent fewer children than heterosexual men.

WHY ARE PEOPLE GAY? GAY BY CHOICE OR IS BEG GAY GEIC?

Your gen terme your sexual orientatn, study suggtsA NEW study parg the DNA of homosexual and heterosexual men uld prove that sexual orientatn is rooted a person’s HAS long been bated whether sexual orientatn is a rult of a person’s blogy or is termed by environmental factors and outsi fluenc. Scientists pared the whole genom of around 1000 homosexual men and 1200 heterosexual men and found there were two specific DNA regns that differed between the of the regns alt wh a gene that plays an important role bra velopment and hormone productn, which uld also be lked to a person’s sexual other gene is lked to thyroid functn, which is an area prevly been lked wh sexual orientatn, acrdg to the thors of the some geic differenc were found the areas, the rearchers have utned that the rults are “bt scribed as speculative”, but still leave rearchers a step closer to unrstandg how sexual preferenc velop. “As this study was rried out European men, we do not know whether the fdgs will apply to homosexualy women, or even to homosexualy non-European men.

“All that is required to see a geic associatn this study is for slightly more homosexual men to rry the geic variant than heterosexual men, and many tim this will simply be due to chance. 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.

SCIENTISTS FD DNA DIFFERENC BETWEEN GAY MEN AND THEIR STRAIGHT TW BROTHERS

“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.

NO ‘GAY GENE’: MASSIVE STUDY HOM ON GEIC BASIS OF HUMAN SEXUALY

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 would unrme arguments that beg gay is a social or liftyle choice.

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.

THERE’S NO ONE ‘GAY GENE,’ BUT GEICS ARE LKED TO SAME-SEX BEHAVR, NEW STUDY SAYS

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.

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.

THERE’S (STILL) NO GAY GENE

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.

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.

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

“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.