超級富豪也將成爲健康超人
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.
如果說人類基因組是生命之書，那麼Crispr技術就是用來編寫這本書的Microsoft Word。這種基因“剪切和粘貼”技術3年前才問世，可用於從初露端倪的基因組中剪除DNA片段，如有需要，還可向基因組中插入新的片段。
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.
這種修改是永久性的，可以代代相傳。這種技術可以用於小鼠和人類；中國的一個科研小組最近透露，他們從一個人類胚胎上切除β-地中海貧血症（一種遺傳性血液疾病）基因的操作取得了部分成功。奇怪的是，這種可能界定人類未來的技術還未震驚社會。
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“規律成簇的間隔短迴文重複”(clustered regularly interspaced short palindromic repeats)的簡稱，是一套新的基因編輯技術中最簡單的一種，借鑑了細菌的免疫系統。當細菌遭到病毒的入侵時，會使用“分子剪刀”——一種DNA內切酶來切掉入侵者。將分子剪刀與一個能將“刀鋒”引導到特定點的分子進行配對，你就能夠對基因組進行編輯了。DNA被切除後，細胞修復機制開始發揮作用，接合斷裂的部分，胚胎繼續發育。這就是中國科學家從人類胚胎中去除突變基因的方法。
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.
這一切除還不完美。由於實驗是在一個不能存活的胚胎上進行的，我們永遠無從得知這個胚胎能否發育成一個不會患地中海貧血症的嬰兒。儘管如此，這項研究極富爭議性，以至於《自然》(Nature)和《科學》(Science)都拒絕發表這項研究。但該研究今年4月發表在別處，引發了一場仍在激烈展開的辯論。以美國生物學家爲主的一組科學家呼籲中止研究，指出對人類生殖細胞系的修改（這種修改會代代相傳）是一條不可輕率跨過的界線。在嚴格的監管制度下工作的英國科學家考慮到對基礎科學構成的風險，不願呼應前者的呼籲。
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)也不太情願阻礙基礎研究，她是Crispr技術的發明者之一，去年贏得了300萬美元的“突破獎”(Breakthrough Prize)（很多人認爲她還將獲得諾貝爾獎）。然而，美國政界人士焦慮不安；國會正在考慮一項禁止美國食品藥品監督管理局(FDA)批准人類胚胎相關臨牀應用的法案。
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.
在基因組層面消除人類疾病，將影響個人及其所有後代，這需要實驗室以外的社會各界進行考量——哲學家、律師、宗教人士和公衆。而這些人現在缺席。在英國，人們正在熱烈討論使用捐獻的線粒體DNA生育“三親嬰兒”的前景；但基因組編輯能夠做到更加偉大的事情，它會影響我們獲得遺傳特徵的來源——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.
目前新基因插入還未在人類胚胎上進行過，這種技術提出了更多問題。如果我向一個胚胎插入一套基因，使其獲得對埃博拉、癌症和阿爾茨海默病的抗性，我是否創造了一個超人？完美的健康會不會成爲超級富豪的專屬？美國的Editas Medicine等初創公司已經啓動這場豪賭。有一天，未曾進行基因修改的人或許會和更年輕、進行過基因編輯的一代人共同生活在一個世界上。
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.
這場討論還未完全公開，或許是因爲基因編輯技術比較複雜，也可能是因爲不像線粒體疾病的相關技術，這場辯論無法用催人淚下的個人故事大做文章。英國慈善機構納菲爾德生命倫理委員會(Nuffield Council on Bioethics)正在考慮基因組編輯；該委員會的意見讓人期待。
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.
在我們繼續摸索之際，一個合適的類比是把我們自己想象成一本用基因語言書寫的精彩的書。在某個時間點，社會必須決定，是不是有任何人應該成爲一篇完美的散文，還是該保持現狀，繼續做一篇未經編輯的、結尾不可預測的驚險小說？
