Scientists have edited human embryos² for the first time in the UK to discover a "master gene" that underpins³ successful pregnancies⁴. The "game-changing" research promises improved IVF outcomes and a breakthrough in understanding why so many pregnancies fail.

科学家首次在英国对人类胚胎进行编辑，他们发现了一种为妊娠成功奠定基础的"主导基因"。这项"划时代"的研究有望提高体外受精成功率，并有助于了解很多人妊娠失败的原因。

The Government-funded investigation⁵, undertaken by the Francis Crick Institute, is the first to prove that gene editing can be used to study the genetic⁶ behavior of human embryos in their first few days of life.

弗兰西斯克里克研究所在政府的资助下进行了这项研究，首次证明可以利用基因编辑研究人类胚胎发育最初阶段的遗传行为。

By removing a gene called OCT4, which produces a protein, the team discovered it was crucial to a viable⁷ pregnancy⁸.

通过移除一种名为OCT4的蛋白质生成基因，研究团队发现，该基因正是成功妊娠的关键。

As well as its potential for more successful IVF, the discovery heralds⁹ a transformation¹⁰ in understanding the fundamental causes of infertility¹¹ and miscarriage¹².

这一发现预示着人们对流产和不孕的根本原因的认识将发生改变，也预示着试管婴儿的成功率可能将提高。

Approximately one in four couples are affected¹³ by fertility problems, and women under 35 currently have just a 32.2 percent chance of a live birth from one round of IVF.

大约有1/4的夫妇受不孕不育的困扰，目前，35岁以下的女性单次体外受精生下活胎的几率只有32.2%。

The odds¹⁴ decrease to 27.7 for women aged 35 to 37, and to 20.8 percent for those aged 38 and 39.

35岁到37岁之间的女性单次体外受精生下活胎的几率则下降到27.7%，而38、39岁的女性则下降到20.8%。

Dr Kathy Niakan, who led the research, said: "One way to find out what a gene does in the developing embryo¹ is to see what happens when it isn't working.

该研究的领头人凯西·尼亚肯博士表示："想要了解一种基因对发育中胚胎的影响，方法之一就是看当它失效时会发生什么。"

"Now we have demonstrated an efficient way of doing this, we hope that other scientists will use it to find out the roles of other genes¹⁵.

"现在，我们已经证明这种方法的有效性，我们希望其他科学家也能在研究其他基因的作用时使用这种方法。"

"If we knew the key genes that embryos need to develop successfully, we could improve IVF treatments and understand some causes of pregnancy failure."

"如果我们了解了胚胎成功发育所需的关键基因，那么我们就可以提高试管婴儿技术，并搞清楚导致妊娠失败的一些原因。"

The scientists, who studied 41 human embryos donated by IVF patients, used the gene-editing tool Crispr/Cas9 to make precise cuts in DNA¹⁶ and deactivate¹⁷ OCT4.

科学家们对接受体外受精的患者捐献的41个人类胚胎进行了研究，使用Crispr/Cas9基因编辑工具精准地切割DNA，令OCT4基因失效。

They found OCT4 appeared to be necessary for an embryo to become a blastocyst, a tiny ball of 200 cells that arises a week after conception and marks a key point in embryonic¹⁸ development.

他们发现OCT4基因似乎是胚胎发育成囊胚的必要因素，囊胚是由200个细胞组成的小球体，在受精后一周左右开始出现，是胚胎发育的关键节点。

Only when an embryo successfully reaches the blastocyst stage does it stand any chance of implanting in the womb.

只有当胚胎成功进入囊胚期，才有可能植入子宫中。

The study, published in the journal Nature, found fewer than a fifth of the test embryos reached the blastocyst stage without OCT4.

这项发表在《自然》杂志上的研究发现，当缺乏OCT4基因时，进入囊胚期的实验胚胎不到1/5。