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
• THERE'S NO SUCH THG AS A 'GAY GENE,' A NEW STUDY ARGU
• WHAT DO THE NEW ‘GAY GEN’ TELL ABOUT SEXUAL ORIENTATN?
• SCIENTISTS SAY THEY N PREDICT IF SOMEONE IS GAY BY LOOKG AT DNA
• WHY ARE PEOPLE GAY? GAY BY CHOICE OR IS BEG GAY GEIC?
• SCIENTISTS FD DNA DIFFERENC BETWEEN GAY MEN AND THEIR STRAIGHT TW BROTHERS
• 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
• IS THERE A 'GAY GENE'? THE PROBLEM WH STUDI NNECTG GEICS AND LGBTQ INTY
• STUDY: DNA TT N PREDICT WHETHER YOU ARE GAY
• THE LIFE OF THE GAY GENE: OM HYPOTHETIL GEIC MARKER TO SOCIAL REALY
• IS BEG GAY YOUR DNA? HOMOSEXUAL MEN SHARE TWO GENE VARIANTS THAT SUGGT THEY ARE BORN WH THEIR SEXUAL PREFERENCE, CLAIMS NTROVERSIAL STUDY

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

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. 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 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.

THERE'S NO SUCH THG AS A 'GAY GENE,' A NEW STUDY ARGU

“[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. In the years sce, the ncept of a “gay gene” has been a source of bate wh both the scientific muny and the general public, spirg ever-larger follow-up studi over the years. In fact, Ganna says the rearch suggts that measur like the Ksey Sle, which argue that sexualy exists on a spectm om totally gay to totally straight, are overly simplistic.

” The study leav many qutns unanswered, part bee alt wh a fairly homogeno sample: people of European anctry, many of whom me of age durg a time when homosexualy was highly stigmatized or even crimalized. 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.

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

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.

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.

They asked more than 477, 000 participants whether they had ever had sex wh someone of the same sex, and also qutns about sexual fantasi and the gree to which they intified as gay or straight.

SCIENTISTS SAY THEY N PREDICT IF SOMEONE IS GAY BY LOOKG AT DNA

“A lot of people want to unrstand the blogy of homosexualy, and science has lagged behd that human tert, ” says William Rice, an evolutnary geicist at the Universy of California, Santa Barbara, who also was not volved the work.

Scientists claim they n predict whether someone is gay or straight wh up to 70 per cent accuracy by lookg at their has long been believed that sexualy has a blogil basis – wh certa gen lked to beg the claim sexual behavur n be predicted by such a high gree was scribed as 'bold' by Brish scientists. They claim to be able to predict whether someone is gay (illtrated) or straight wh 70 per cent accuracyThe fdgs do not show whether a tt would show whether a child would grow up to be gay or not – as the rearch was rried out on our gen are termed at birth – tags on the gen which affect how they work n change over time bee of factors the environment, or the womb.

'TOMBOY GENE' LINKED TO PROMISCUITY Girls who are tomboys grow up to have more lovers whether they are straight or gay, a study has seems the gen that make women more mascule may also make them more promiscuo, rearchers fdg helps expla why homosexualy don’t die out, even though lbian upl are not able to naturally have children rryg the gen of each is bee straight tomboys have more lovers than others – and so the ‘tomboy DNA’ stays circulatn, acrdg to the study rried out by a team om Kg’s College London. This fdg has led scientists to believe there is a geic ponent to beg ppot the geic areas which are lked to some people beg gay, Dr Ngun and his team studied the gen of 47 pairs of adult male intil study volved 37 pairs of tws which one brother was homosexual and the other heterosexual, and 10 pairs which both were a puter program lled Fuzzy Fort they found that ne small regns of the geic played the key role on cidg whether someone is heterosexual or rearch looked at a procs lled 'methylatn' of the DNA – which has been pared to a swch on the DNA – makg have a stronger or weaker effect. This alteratn of the gene is known as an 'epigeic' rearchers, who are due to prent their fdgs at the Amerin Society of Human Geics 2015 Annual Meetg Baltimore, say they found distct patterns of methylatn on the DNA that seem to be associated wh homosexualy.

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

'The fdgs, however, do not mean scientists uld predict the sexualy of a child before is born – as the tts were rried out on ppotg distct geic patterns that seem to play a role termg whether someone is gay or straight, uld nceivably be a step towards creatg a tt for such tt would be highly ntroversial – not to say uhil – as rais the possibily unscpulo scientists uld try to ci the future sexualy of ‘signer babi’. Commentg on the rearch, Profsor Tim Spector, om Kg's College London, a leadg expert on tw studi and geics, said: 'It has always been a mystery why intil tws who share all their gen n vary homosexualy.

' Scientists say further rearch will be need to validate whether the patterns seen on the DNA of gay men (pictured) are reflected larger populatns. They say claims about predictg homosexualy are 'bold'Darren Griff, profsor of geics at the Universy of Kent, said: 'To claim a 70 per cent predictive value of somethg as plex as homosexualy is bold ed.

'While there is strong evince general for a blogil basis for homosexualy my personal imprsn has always been one of a multiple ntributory factors, cludg life experienc. 'Dr Christopher Gregg, Assistant Profsor of Nroblogy & Anatomy and Human Geics, Universy of Utah said:'Overall, the importance of the fdgs will hge on how reproducible they are future studi that clu larger groups of heterosexual and homosexual dividuals. ' Gay and human rights mpaigner Peter Tatchell said: ‘This rearch claims to be able to predict sexual orientatn wh 'up to' 70 per cent accuracy.

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

It very much appears that same-sex sexual attractn is not a choice but actg on is; so if you fe gay as the mere prence of same-sex attractn, then om everythg we unrstand, beg gay is not a choice. If, on the other hand, you nsir someone to be gay only if they act on their same-sex attractn then beg gay n be nsired a choice pendg on an dividual's behavr. Ngun reported that studyg the geic material of 47 pairs of intil male tws, he has intified “epigeic marks” ne areas of the human genome that are strongly lked to male dividuals, said Ngun, the prence of the distct molecular marks n predict homosexualy wh an accuracy of close to 70%.

Geicists suggt that together, the human genome and s epigenome reflect the teractn of nature and nurture -- both our fixed herance and our bodi’ flexible rpons to the world -- makg who we ’s study of tws don’t reveal how or when a male tak on the epigenomic marks that distguish him as homosexual. ”To fd the epigenomic markers of male homosexualy, Ngun, a postdoctoral rearcher at UCLA’s Geffen School of Medice, bed through the geic material of 47 sets of intil male tws. But the existence of tw pairs which one is homosexual and the other is not offers strong evince that somethg other than DNA alone fluenc sexual orientatn.

So they unleashed a mache learng algorhm on the data to search for regulari that distguished the epigenom of homosexual tw-pairs om tws which only one was ne pact regns sttered across the genome, they found patterns of epigenomic differenc that would allow a predictn far more accurate than a random gus of an dividual’s sexual orientatn, Ngun reported Thursday. McCarthy and other experts utned that the disvery of epigenomic marks suggtive of homosexualy is a far cry om fdg the of sexual distctive epigenomic marks observed by Ngun and his lleagu uld rult om some other blogil or liftyle factor mon to homosexual men but unrelated to their sexualy, said Universy of Utah geicist Christopher Gregg.

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

But the existence of intil tw pairs which only one is homosexual “nclively suggt that gen don’t expla everythg, ” Bailey Ngun’s rearch needs to be replited larger studi of tws, advanc the fful procs of better unrstandg how — and when — a boy’s sexual orientatn velops, Bailey me on Twter @LATMelissaHealy and “like” Los Angel Tim Science & Health on rarely get ncer, now scientists thk they know whyThree rearchers w Nobel Prize chemistry for studi of DNA repairMars had a long-lastg seri of lak, NASA’s Cursy rover fds.

“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. 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.

IS THERE A 'GAY GENE'? THE PROBLEM WH STUDI NNECTG GEICS AND LGBTQ INTY

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. 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. 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. 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.

STUDY: DNA TT N PREDICT WHETHER YOU ARE GAY

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.

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

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. “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.

IS BEG GAY YOUR DNA? HOMOSEXUAL MEN SHARE TWO GENE VARIANTS THAT SUGGT THEY ARE BORN WH THEIR SEXUAL PREFERENCE, CLAIMS NTROVERSIAL STUDY

In theory, humans and other animals who are exclively attracted to others of the same sex should be unlikely to produce many blogil children, so any gen that predispose people to homosexualy would rarely be passed on to future generatns. Yet same-sex attractn is wispread humans, and rearch suggts that is partly a study of data om hundreds of thoands of people, rearchers have now intified geic patterns that uld be associated wh homosexual behavur, and showed how the might also help people to fd different-sex mat, and reproduce.

The thors say their fdgs, published on 23 Augt Nature Human Behavur1, uld help to expla why gen that predispose people to homosexualy ntue to be passed down. Most of the participants were born durg a time when homosexualy was eher illegal or culturally taboo their untri, so many people who were attracted to others of the same sex might never have actually acted on their attractn, and uld therefore have end up the wrong group the Monk, an elogist and evolutnary blogist at Yale Universy New Haven, Connecticut, thks that the veats are so important that the paper n’t draw any real nclns about geics and sexual orientatn.

Instead, he thks the rearchers have found geic markers associated wh openns to new experienc, which uld expla the overlap between people who have had a homosexual partner and heterosexual people who have had many partners. And he adms that g a sgle homosexual experience as an ditn of sexual orientatn isn’t ial, but says that the UK Bbank didn’t provi data on attractn. The largt study to date on geics and same-sex sexual behavr was published last week, and nclud somethg many queer people have been sayg for a long time: Sexual orientatn is plited and n’t be explaed away by a sgle “gay gene.