Genes¹ linked to homosexuality have been discovered by scientists in the biggest ever study into the genetic² basis for sexual orientation³.

在迄今为止最大规模的针对性取向遗传基础的研究中，科学家发现了与同性恋相关的基因。

For the first time, researchers looked at the complete genome - a person's entire DNA⁴ code - for more than 1,000 gay men and compared it to genetic data from a similar number of heterosexual males.

研究人员首次研究了1000多名同性恋男性的完整基因组--即个人全部的DNA代码，并将其与类似数量的异性恋男子的基因数据进行比较。

They discovered that DNA was different for gay and straight men around the genes SLITRK5 and SLITRK6.

他们发现，同性恋和异性恋男子在SLITRK5和SLITRK6两种基因上存在差异。

SLITRK6 is an important gene for brain development, and is particularly active in a region of the brain which includes the hypothalamus.

SLITRK6是一种促进大脑发育的重要基因，在包括下丘脑的大脑区域尤为活跃。

The hypothalamus is crucial for producing the hormones⁵ which control sex drive, and previous studies have shown parts of it are up to 34 per cent larger in gay men.

下丘脑对于产生控制性冲动的激素至关重要，以往的研究表明，同性恋男子下丘脑的某些部位比普通人要大出34%。

The researchers, from North Shore University Health System's Research Institute, in Illinois, US, also discovered differences in the TSHR gene, which is linked to the thyroid, another area which has previously⁶ been associated with sexual orientation.

美国伊利诺伊州北岸大学卫生系统研究学院的研究人员还发现了TSHR基因中的差别，这种基因与甲状腺有关，而之前的研究发现甲状腺也影响性取向。

"Because sexuality is an essential part of human life – for individuals and society – it is important to understand the development and expression of human sexual orientation," said lead author Dr Alan Sanders.

该研究的第一作者艾伦·桑德斯说：“由于性行为是人类生活必不可少的一部分，理解人类性取向的发展和表达很重要。”

"The goal of this study was to search for genetic underpinnings of male sexual orientation, and thus ultimately increase our knowledge of biological mechanisms⁷ underlying⁸ sexual orientation."

“这项研究的目的是寻找男性性取向的基因基础，从而最终提高我们对性取向的生物学机制的认识。”

"What we have accomplished⁹ is a first step for genome wide study on the trait, and we hope that subsequent larger studies will further illuminate¹⁰ its genetic contributions."

“我们已经完成了这个特性全基因组研究的第一步，我们希望后续的更大规模的研究将进一步阐明其基因作用。”

Participants in the study were rated for sexual orientation based on their self-reported sexual identity and sexual feelings. Men were asked to provide DNA by blood or saliva¹¹ samples that were then genotyped and analysed.

研究根据参与者自述的性身份和性感受来将他们的性取向分级，还通过他们血液或唾液样本提供的DNA进行基因分析。

Although previous studies have pointed¹² to a genetic predisposition for homosexuality, it is the first time researchers have studied the entire genome of individuals and so is the most comprehensive assessment¹³ of the genetic basis of sexuality ever undertaken.

尽管以往也有研究指出同性恋具有基因诱因，但本次是研究人员首次研究个人的全部基因组，是对性基因基础的最全面评估。

However British experts said more work was needed before it was possible to identify 'gay genes' because the genetic differences could point to other traits shared by the homosexual respondents.

不过，英国专家表示，在有可能确认“同性恋基因”之前，还有许多工作要做，因为基因差异可以指向同性恋者所共有的其他特征。