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.
假如說人類基因組是性命之書,那末Crispr技巧便是用來編寫這本書的Microsoft Word。這類基因“剪切和粘貼”技巧3年前才問世,可用於從初露眉目的基因組中剪除DNA片斷,若有須要,還可向基因組中插入新的片斷。
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.
這類修正是永遠性的,可以代代相傳。這類技巧可以用於小鼠和人類;中國的一個科研小組比來泄漏,他們從一小我類胚胎上切除β-地中海血虛癥(一種遺傳性血液疾病)基因的操縱獲得了部門勝利。奇異的是,這類大概界定人
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“紀律成簇的距離短回文反復”(clustered regularly interspaced short palindromic repeats)的簡稱,是一套新的基因編纂技巧中最簡略的一種,鑒戒了細菌的免疫體系。當細菌受到病毒的入侵時,會應用“份子鉸剪”——一種DNA內切酶來切掉入侵者。將份子鉸剪與一個能將“刀鋒”引誘到特定點的份子舉行配對,你就可以對基因組舉行編纂了。DNA被切除後,細胞修復機制開端施展感化,接合斷裂的部門,胚胎持續發育。這便是中國科學家從人類胚胎中去除突變基因的辦法。
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.
這統統除還不完善。因為試驗是在一個不克不及存活的胚胎上舉行的,咱們永久無從得悉這個胚胎可否發育成一個不會患地中海血虛癥的嬰兒。只管如斯,這項研討極富爭議性,以致於《天然》(Nature)和《科學》(Science)都謝絕揭櫫這項研討。但該研討本年4月揭櫫在別處,激發了一場仍在劇烈睜開的爭辯。以美國生物學家為主的一組科學家號令中斷研討,指出對人類生殖細胞系的修正(這類修正會代代相傳)是一條弗成草率跨過的界限。在嚴厲的羈系軌制下事情的英國科學家斟酌到對基本科學組成的危害,不肯呼應前者的號令。
This reluctance to impede fundamental research is shared by Jennifer Doudna of University of California, Berkeley, who co-invented Crispr and won a $3m Breakthrough prize last year (she is also tipped for a Nobel). US politicians, however, are twitchy; a proposal being considered in Congress would ban the Food and Drug Administration from approving clinical applications in human embryos.
美國加州大學伯克利分校(University of California, Berkeley)的珍妮弗•杜德納(Jennifer Doudna)也不太寧願攔阻基本研討,她是Crispr技巧的創造者之一,客歲博得了300萬美元的“沖破獎”(Breakthrough Prize)(許多人以為她還將得到諾貝爾獎)。但是,美國官場人士焦炙不安;國會正在斟酌一項制止美國食物藥品監視治理局(FDA)同意人類胚胎相幹臨床運用的法案。
The cancellation of human disease at genome level, which affects an individual and all their descendants, requires contemplation beyond the laboratory — by philosophers, lawyers, clerics and the public. This has been absent. In the UK there has been febrile discussion over the prospect of creating “three-parent babies”using donated mitochondrial DNA; but genome editing could be capable of far greater things, and affects nuclear DNA — from which we derive our genetic identity.
在基因組層面清除人類疾病,將影響小我及其全部子女,這須要試驗室之外的社會各界舉行考量——哲學家、狀師、宗教人士和"大眾,"。而這些人如今缺席。在英國,人們正在熱鬧評論辯論應用募捐的線粒體DNA生養“三親嬰兒”的遠景;但基因組編纂可以或許做到加倍巨大的工作,它會影響咱們得到遺傳特點的起源——核DNA。
Inserting new genes, which has yet to be carried out in human embryos, raises further questions. If, in one embryo, I paste in a royal flush of genes conferring resistance to Ebola, cancer and Alzheimer’s, have I created a superhuman? Will perfect health become the preserve of the super-rich? Start-ups such as Editas Medicine of the US are already gambling on this. We may one day have unaltered people living alongside a younger, gene-edited generation.
今朝新基因插入還未在人類胚胎上舉行過,這類技巧提出了更多題目。假如我向一個胚胎插入一套基因,使其得到對埃博拉、癌癥和阿爾茨海默病的抗性,我是不是發明了一個超人?完善的康健會不會成為超等富豪的專屬?美國的Editas Medicine等始創公司已啟動這場豪賭。有一天,不曾舉行基因修正的人大概會和更年青、舉行過基因編纂的一代人配合生存在一個天下上。
That the discussion has not gone fully public might be because genome- editing technology is complex — and because, unlike with mitochondrial disease, there are no heart-wrenching personal tales on which to hang the debate. The Nuffield Council on Bioethics, a UK-based charity, is considering genome-editing; its views cannot come too soon.
這場評論辯論還未完整公然,大概是由於基因編纂技巧比擬龐雜,也多是由於不像線粒體疾病的相幹技巧,這場爭辯沒法用催人淚下的小我故事大做文章。英國慈善機構納菲爾德性命倫理委員會(Nuffield Council on Bioethics)正在斟酌基因組編纂;該委員會的看法讓人等待。
Imagining ourselves as glorified books, penned in the language of genes, is a fitting analogy as we muddle on. At some point, society must decide whether any person deserves to be a perfect piece of prose, or whether we should each remain an unedited thriller with an unpredictable ending.
在咱們持續探索之際,一個適合的類比是把咱們本身想象成一本用基因說話謄寫的出色的書。在某個時光點,社會必需決議,是否是有任何人應當成為一篇完善的散文,照樣該堅持近況,持續做一篇未經編纂的、末端弗成猜測的驚險小說?