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　　If the human genome is the book of life, then Crispr technology is its Microsoft Word. The cut-and-paste technique, invented only three years ago, can be used on fledgling genomes to snip out bits of DNA and, if required, insert new stretches.

　　如果说人类基因组是生命之书，那么Crispr技术就是用来编写这本书的Microsoft Word。这种基因“剪切和粘贴”技术3年前才问世，可用于从初露端倪的基因组中剪除DNA片段，如有需要，还可向基因组中插入新的片段。

The amendments are permanent and can be passed down the generations. The technology works on mice and men; a team in China recently revealed they had partially succeeded in excising the gene for beta thalassaemia, an inherited blood disorder, from a human embryo. It is a wonder society is not yet spooked by what could be a defining technology for the future of humanity.

　　这种修改是永久性的，可以代代相传。这种技术可以用于小鼠和人类;中国的一个科研小组最近透露，他们从一个人类胚胎上切除β-地中海贫血症(一种遗传性血液疾病)基因的操作取得了部分成功。奇怪的是，这种可能界定人

　　Crispr — short for clustered regularly interspaced short palindromic repeats — is the simplest of a suite of new gene-editing technologies, and is a trick borrowed from the bacterial immune system. Bacteria, when invaded by a virus, deploy “molecular scissors” — a DNA-cutting enzyme that chops up the invader. Pair the scissors with a guiding molecule capable of directing the blades to a specific point, and you are ready to edit a genome. After the DNA is severed, cellular repair machinery kicks in to close the gap and the embryo continues to develop. This is how the Chinese scientists banished the mutant gene from their human embryo.

　　Crispr是“规律成簇的间隔短回文重复”(clustered regularly interspaced short palindromic repeats)的简称，是一套新的基因编辑技术中最简单的一种，借鉴了细菌的免疫系统。当细菌遭到病毒的入侵时，会使用“分子剪刀”——一种DNA内切酶来切掉入侵者。将分子剪刀与一个能将“刀锋”引导到特定点的分子进行配对，你就能够对基因组进行编辑了。DNA被切除后，细胞修复机制开始发挥作用，接合断裂的部分，胚胎继续发育。这就是中国科学家从人类胚胎中去除突变基因的方法。

　　The deletion was not perfect. It was carried out in a non-viable embryo so we will never know if it would have developed into a thalassaemia-free baby. Nonetheless, the research was so controversial that both Nature and Science declined to publish it. But publication elsewhere in April ignited a debate that still burns. A group of mostly US biologists has called for a moratorium, noting that modifications to the human germ line (changes that would be passed down generations) constituted a Rubicon not to be crossed lightly. UK scientists, working in a tight regulatory regime, are loath to back this call given the risk to basic science.

　　这一切除还不完美。由于实验是在一个不能存活的胚胎上进行的，我们永远无从得知这个胚胎能否发育成一个不会患地中海贫血症的婴儿。尽管如此，这项研究极富争议性，以至于《自然》(Nature)和《科学》(Science)都拒绝发表这项研究。但该研究今年4月发表在别处，引发了一场仍在激烈展开的辩论。以美国生物学家为主的一组科学家呼吁中止研究，指出对人类生殖细胞系的修改(这种修改会代代相传)是一条不可轻率跨过的界线。在严格的监管制度下工作的英国科学家考虑到对基础科学构成的风险，不愿呼应前者的呼吁。