Home>News Center>Life
         
 

Moms' genetics might help produce gay sons
(HealthDay)
Updated: 2006-02-23 09:19

New research adds a twist to the debate on the origins of sexual orientation, suggesting that the genetics of mothers of multiple gay sons act differently than those of other women.

Scientists found that almost one fourth of the mothers who had more than one gay son processed X chromosomes in their bodies in the same way. Normally, women randomly process the chromosomes in one of two ways -- half go one way, half go the other.

The research "confirms that there is a strong genetic basis for sexual orientation, and that for some gay men, genes on the X chromosome are involved," said study co-author Sven Bocklandt, a postdoctoral researcher at the University of California at Los Angeles.

The link between genetics and sexual orientation has been a hot topic for more than a decade as a few scientists have tried to find genes that might make people gay or straight. In the new study, Bocklandt and colleagues examined a phenomenon called "X-chromosome inactivation."

While females have two X chromosomes, they actually require only one and routinely inactivate the other, Bocklandt said. "That way, both men and women have basically one functional X chromosome," he added. Men have both an X and Y chromosome, but the Y chromosome plays a much smaller role, he said.

Women typically inactivate one of their two X chromosomes at random. "It's like flipping a coin," Bocklandt said. "If you look at a woman in any given (bodily) tissue, you'd expect about half of the cells to inactivate one X, and half would inactivate the other."

In the new study, researchers looked at 97 mothers of gay sons and 103 mothers without gay sons to see if there was any difference in how they handled their X chromosomes. The findings appear in the February issue of the journal Human Genetics.

"When we looked at women who have gay kids, in those with more than one gay son, we saw a quarter of them inactivate the same X in virtually every cell we checked," Bocklandt said. "That's extremely unusual."

Forty-four of the women had more than one gay son.

In contrast, 4 percent of mothers with no gay sons activated the chromosome and 13 percent of those with just one gay son did.

The phenomenon of being more likely to inactivate one X chromosome -- known as "extreme skewing" -- is typically seen only in families that have major genetic irregularities, Bocklandt said.

What does this all mean? The researchers aren't sure, but Bocklandt thinks he and his colleagues are moving closer to understanding the origins of sexual orientation.

"What's really remarkable and very novel about this is that you see something in the bodies of women that is linked to a behavioral trait in their sons," he said. "That's new, that's unheard of."

Still, there are caveats. Dr. Ionel Sandovici, a genetics researcher at The Babraham Institute in Cambridge, England, pointed out that most of the mothers of multiple gay sons didn't share the unusual X-chromosome trait. And the study itself is small, which means more research will need to be done to confirm its findings, Sandovici said.

Ultimately, Sandovici added, the origins of sexual orientation remain "rather a complicated biological puzzle."

And this line of research does have its critics. Some have worried that, in the future, manipulation of a "gay gene" or genes might be used as a method of preventing homosexuality in utero, or perhaps even after. But Bocklandt said these kinds of fears shouldn't stand in the way of legitimate scientific research.

"We're trying to understand one of the most critical human traits: the ability to love and be attracted to others. Without sexual reproduction we would not exist, and sexual selection played an essential role in evolution," he said. "Yet, we have no idea how it works, and that's what we're trying to find out. As with any research, the knowledge you acquire could be used for benefit or harm. But if [scientists] would have avoided research because we were afraid of what we were going to find, then we would still be living in the stone age."



Zhang Ziyi in revealing photos
Premiere of 'Madea's Family Reunion'
Leung, mystery writer join forces
  Today's Top News     Top Life News
 

State firm executives to get stock options from March 1

 

   
 

Chen warned not to pursue secession

 

   
 

Strict curbs pledged on land acquisition

 

   
 

Human trials begin for anti-HIV drug

 

   
 

Eight co-workers share US$365m jackpot

 

   
 

Fossil find 'may rewrite history'

 

   
  Americans work more, seem to accomplish less: Study
   
  Moms' genetics might help produce gay sons
   
  Former UN spokesman now teaching in China
   
  Two naked actresses draw magazine buzz
   
  Global spread of English threatens US, UK
   
  Job hopping rampant as skilled workers chased
   
 
  Go to Another Section  
 
 
  Story Tools  
   
  Feature  
  Could China's richest be the tax cheaters?  
Manufacturers, Exporters, Wholesalers - Global trade starts here.
Advertisement
         
主站蜘蛛池模板: 亚洲毛片无码专区亚洲乱| 精品视频一区二区三区在线播放| 高潮插的我好爽再干噢在线欢看 | 在线a毛片免费视频观看| 国农村精品国产自线拍| 国产精品久久国产精麻豆99网站 | 国产国产人免费人成成免视频| 国产一级视频免费| 亚洲黄色高清视频| 亚洲va久久久噜噜噜久久天堂| 久久人人爽天天玩人人妻精品| 三上悠亚ssni_229在线播放| 80s国产成年女人毛片| 高h黄全肉一女n男古风| 美女**视频一级毛片| 欧美末成年video水多| 日本国产在线视频| 在线观看高嫁肉柳1一4集中文 | 99RE66在线观看精品免费| 黄瓜视频入口在线播放| 精品人妻少妇一区二区| 欧美在线一级视频| 无码免费一区二区三区免费播放| 在线观看国产亚洲| 国产人妖ts在线观看免费视频| 亚洲综合无码一区二区| 久久亚洲精品无码观看不卡| 99久久精品美女高潮喷水| 青青青久97在线观看香蕉| 毛片a级毛片免费观看免下载| 日本熟妇色熟妇在线视频播放| 在线观看二区三区午夜| 国产一区在线观看免费| 亚洲欧美日韩图片| 中文字幕中出在线| 欧美在线色视频| 男攻在开会男受在桌子底下 | 爽好舒服使劲添我要视频| 日本高清视频wwww色| 国产麻豆交换夫妇| 和黑帮老大365天完整版免费|