A study conducted in the US, the UK and China showed that up to a quarter of men around the world have a genetic defect that could reduce their chances of having children.
Scientists have found some sperm lacks a protectiveprotein gene that helps it to reach the egg.
The protein gene, called DEFB126, coats the sperm and allows it to penetrate mucus in the female reproductive tract. It also protects the sperm from attack by the female immune system.
Without a protectiveprotein barrier, sperm struggles to reach its goal. It reduces 30 percent of pregnant rate of his partner.
"In 70 percent of infertile men, you can't explain their infertility on the basis of sperm count and quality. The discovery could help explain a significantproportion of male infertility worldwide," said lead researcher Professor Gary Cherr, from the University of California at Davis.
The study can also bring the new methods of screening and curing infertility.
A test for defective DEFB126 could help fertility clinics decide whether couples should be given ICSI treatment (intracytoplasmic sperm injection).
The research is published today in the journal Science Translational Medicine.


据英国《每日邮报》21日报道，一项由中美英共同完成的研究表明，全球有超过1/4的男性可能会因遗传缺陷而导致不育几率增加。

科学家发现一些男子体内的精子缺少一种防护型蛋白质基因，而这种基因的功能就是帮助精子和卵子相遇。

名为DEFB126的蛋白质基因覆盖在精子表面，并帮助精子穿过女性的子宫颈黏液。同时，DEFB126蛋白质也可保护精子免受女性免疫系统的伤害。

如果没有这种起保护作用的蛋白质，精子就很难与卵子结合，这样怀孕生育的概率就会降低30%。

领导此项研究的加州大学戴维斯分校教授西奥多•托尔纳说:"70%的男性不育症都并非因为他们的精子数量和质量不达标，这项研究或许有助于揭开这个全球普遍存在的男性不育的谜团。"


这项研究还可能带来检测和治疗不育症的新方法。

对不良DEFB126蛋白质进行检测，或许可以帮助生育诊所的医生抉择是否应该给夫妻们进行单精子注射治疗，即卵胞浆内单精子注射。

该研究发表在今天的美国学术刊物《科学•转化医学》上.

• female [´fi:meil] a.女(性)的 n.女人 (初中英语单词)
• proportion [prə´pɔ:ʃən] n.比率 vt.使成比例 (初中英语单词)
• california [,kæli´fɔ:njə] n.加利福尼亚 (初中英语单词)
• treatment [´tri:tmənt] n.待遇；对待；治疗 (初中英语单词)
• research [ri´sə:tʃ] n.&vi.调查；探究；研究 (初中英语单词)
• journal [´dʒə:nəl] n.日记；日报；杂志 (初中英语单词)
• defect [di´fekt, ´di:fekt] n.缺点，不足 (高中英语单词)
• penetrate [´penitreit] v.贯穿；穿透；渗透 (高中英语单词)
• barrier [´bæriə] n.栅栏；屏障；障碍 (高中英语单词)
• significant [sig´nifikənt] a.重要的；意义重大的 (高中英语单词)
• protective [prə´tektiv] a.防护的；保护贸易的 (英语四级单词)
• defective [di´fektiv] a.有缺陷的；有瑕疵的 (英语四级单词)
• protein [´prəuti:n] n.蛋白质 a.蛋白质的 (英语六级单词)
• pregnant [´pregnənt] a.怀孕的；含蓄的 (英语六级单词)
• fertility [fə:´tiliti] n.肥沃；多产；繁殖力 (英语六级单词)