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Science and technology
科學技術
The 2012 Nobel prizes
諾貝爾生理學獎
Good eggs
再生醫學界的大好人
THIS year's Nobel physiology prize goes to Sir John Gurdon and Shinya Yamanaka for a crucial discovery in stem-cell science?—how to make what are known as pluripotent stem cells from ordinary body cells.
今年的諾貝爾生理學獎頒給了約翰格登爵士和山中伸彌，來表彰他們在干細胞領域的關鍵發現-那就是如何利用普通的體細胞來合成多功能干細胞。
What the citation does not say is that this work also allows clones to be made from adult animals, potentially including people.
諾貝爾頒獎典禮上的褒獎詞沒有指出的是，這項成果使得成年動物 的克隆成為可能，也有可能可以克隆人類。
A stem cell is one that can differentiate into daughter cells specialised for particular functions, and all the cells in a body are thus derived from stem cells.
干細胞是一種可以分化成姐妹細胞的物質，而姐妹細胞則擔當某種特定的功能 ，體內的所有細胞都是來源于干細胞的。
That includes the stem cells themselves, which derive from ur stem cells found in embryos.
而干細胞則是來自胚胎中的ur干細胞。
These embryonic stem cells are the pluripotent cells, meaning they can turn into many other sorts of cell.
這些胚胎干細胞就是多功能干細胞，他們可以分化成很多其他種類的細胞。
Pluripotent embryonic stem cells are of great value to researchers but, if the embryos they came from were human, their use is controversial.
多功能胚胎干細胞對于研究者來講彌足珍貴，但是如果這些胚胎來自于人類，那這些干細胞的使用就有爭議了。
Also, if such cells are ever to play a useful role in medicine, then they will need to be available in bulk—and ideally in a form whose DNA matches that of the recipient.
而且，這些細胞在醫藥方面扮演著如何重要角色， 那么 我們就大量需要這些干細胞了—在理想的情況下，這些干細胞的DNA和接受者的DNA相匹配。
Sir John and Dr Yamanaka have both conducted work that should help make this possible.
格登爵士和山中博士的研究就是來推動這一試想實現的可能性。
Sir John's prizewinning study, published half a century ago, in 1962, when he was at Oxford University, was to transplant the nuclei of cells from adults of a frog called Xenopus laevis into enucleated eggs of that species.
格登爵士的獲獎研究發表于半個世紀前的1962年，當時他正在牛津大學讀書，打算將一只成年非洲爪蟾的細胞核移植到同類的無核卵子中。
The eggs in question then developed into healthy adults.
這些卵子隨后發育成健康的非洲爪蛙。
This showed that DNA is not altered during embryonic development, at least in Xenopus.
這表明DNA在胚胎發育的過程中并未變異，只是在非洲爪蛙的身上沒有發生變異。
It thus suggested it might be possible to get an entire adult cell to perform a similar trick, without involving an egg at all.
這表明很有可能在得到一個成年完整細胞的情況下，通過同樣的試驗，但是不用卵子。
That was what Dr Yamanaka did.
而后者就是由山中博士完成的。
He and his colleagues at Kyoto University managed to activate four crucial genes in adult mouse cells.
在日本京都大學，他和他的同事成功激活了四個成年老鼠細胞中的關鍵基因。
These genes each encode a protein of a type known as a transcription factor, which controls the expression of DNA.
這些基因每個都可以表達生成一種蛋白質，轉錄因子，控制DNA的表達。
Together, they trick the cell in question into thinking it is part of an embryo.
和他的同事一起，他們將試驗細胞看成胚胎的一部分。
In the first experiment, conducted in 2005, Dr Yamanaka did not get complete mice, but he did turn the adult cells into pluripotent stem cells. Subsequent work by his group and others then produced embryos which, if transplanted into the womb of a female mouse, will go all the way to adulthood.
第一個試驗是2005年完成的，山中博士的細胞沒有發育成完整的老鼠，但是博士確實將成年細胞轉化成了多功能胚胎干細胞。他的科研小組隨后生成了這種胚胎，如果將該胚胎植入一只雌性老鼠的子宮內，它就會發育成老鼠。
Finally, in 2007, Dr Yamanaka managed to switch on the same four genes in adult human cells, and thus generated pluripotent human stem cells.
最后，于2007年，山中博士成功轉變了成年人體細胞中的同四種基因，而后生成了多功能人體干細胞。
In principle, that opens the door to human cloning, though no one has tried this in practice—and in most countries such an experiment would be illegal.
理論上，這一研究開啟了人類克隆的大門，盡管還沒有人曾付諸實施-大多數國家，這種試驗都是非法的。
It also opens the door, though, to bespoke tissue repair as it would allow cells of whatever type were desired to be grown from, say, a few skin cells and then transplanted back into the donor without risking an adverse reaction from his immune system.
這一研究也開啟了訂制組織修復的大門，因為可以將任何種類的細胞轉化成別的細胞，比如，一些皮膚細胞被移植回到捐獻者的體內，而不用擔心會對捐獻者的免疫系統造成不良影響。
How well that would work in practice remains to be seen.
在實踐中，這項研究能走多遠，我們拭目以待。
But if it works well then Sir John and Dr Yamanaka may turn out to have been the pioneers of a whole, new field: regenerative medicine.
但是如果成功的話，格登爵士和山中博士就成為一項全新領域的先驅了，那就是再生醫學。
