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Science and technology
科學技術
Human reproduction
人類繁衍
Life begins at 45
45歲也能生娃
Hope for older mothers
高齡母親的福音
WHEN it comes to reproduction, men have it easy.
講到繁衍，男人表示壓力很小。
Almost to the end of their lives most have an ample supply of sperm.
大多數人直到去世前都擁有充足的精子。
Women are not so lucky.
女人可就沒這么幸運了。
They are born with a supply of eggs that typically runs out when they reach middle age.
人到中年，她們就會耗盡出生時攜帶的卵子。
That could be about to change, however.
不過，這一情形很快就能得到改變。
Researchers have confirmed that women harbour ovarian stem cells, and that these can give rise to new eggs.
研究者們證實，女人擁有卵巢干細胞，而這種細胞能成為新的卵細胞的來源。
Stem cells have the ability to divide continuously and to change into different types of cells.
干細胞具有不斷分裂的潛力，可以分化成許多種類的細胞。
Stem cells from adults can produce a variety of cell types, in addition to those that make up the tissue in which they are found.
成人干細胞不僅可以分化成其來源組織的細胞，還能分化成其它細胞。
In 2004 Jonathan Tilly of Harvard Medical School and his colleagues discovered stem cells in mouse ovaries.
2004年，哈弗醫學院的Jonathan Tilly及其同事在老鼠卵巢里發現了干細胞。
Since then it has been shown that these ovarian stem cells can develop into eggs, be fertilised and produce perfectly healthy mouse pups.
迄今已經證實，此類卵巢干細胞能夠分化成為卵細胞，卵細胞在受精后還能發育成健康的鼠寶寶。
But researchers have been reluctant to believe that something similar might be possible in humans.
但是研究者尚不能確信人類也存在類似機能。
Proving that this was indeed the case was tricky.
想要弄清真相有些困難。
Human ovarian tissue—especially from young, healthy donors—is not easy to come by.
人類卵巢組織很難找到，健康的年輕捐獻者的組織更難尋覓。
Dr Tilly’s breakthrough came when he discovered that a former colleague, Yasushi Takai of Saitama Medical University in Japan, had in his freezer healthy ovarian tissue from 30 patients who had changed sex.
幸而Tilly博士發現他的前同事—日本埼玉醫科大學的Yasushi Takai在冰箱里存放了30個變性人不再需要的健康卵巢組織，取得了突破。
Using a sophisticated cell-sorting technique, the researchers developed a way to identify ovarian stem cells that works for both mice and humans.
研究人員運用尖端的細胞分選技術，找出方法，證實人類和老鼠身上都存在卵巢干細胞。
Then they took the human ovarian stem cells, labelled them with a green fluorescent protein and put them back into a slice of human ovary.
隨后，他們分離出人類卵巢干細胞，用熒光蛋白做上標記再把它植入一片人類卵巢組織。
The glowing green cells soon produced a brand new crop of human eggs, according to their findings published this week in Nature Medicine.
這片組織被移植到了活鼠體內，使其保持正常卵巢的機能。他們本周發表在《自然醫學》上的結果稱，這些綠芒閃爍的細胞很快制造出了一批人類卵細胞。
Offshoring fertilisation
國外受精
Fertilising these eggs for experimentation is forbidden in America.
美國禁止為實驗用的卵細胞受精，
Britain’s Human Fertilisation and Embryology Authority, however, will allow it in certain cases.
不過英國的人類受精和胚胎學管理局將在某些研究中允許給卵細胞授精。
So next month Dr Tilly will take some of his stem cell booty to Edinburgh to collaborate with Evelyn Telfer, who has developed a technique for growing human eggs from an early stage.
所以，下個月Tilly博士將帶著卵細胞去愛丁堡與Evelyn Telfer合作。Evelyn Telfer掌握了用卵母細胞培育卵細胞的技術，
She holds a licence to fertilise them experimentally.
持有給試驗用細胞授精的許可。
The discovery could revolutionise infertility treatment for women in several ways.
這項發現會是女性不育癥治療的一場革命。
For one thing, research has shown that in mice, even aged ovaries contain ovarian stem cells.
一方面，老鼠體內衰老的卵巢里也有卵巢干細胞；
And when those stem cells are placed into a young ovary, they will develop healthy eggs.
將這些細胞移植到年輕的卵巢中后，它們能制造健康的卵子。
This raises the possibility that, one day, women of advanced age could have their own biologically related children.
這意味著將來的某天，年齡較大的婦女也能擁有生物學意義上的自己的孩子。
Currently, many women over 45 have to make do with in-vitro fertilisation using the egg of a younger woman.
目前，許多45歲以上的婦女只能湊合著用年輕女人的卵細胞進行體外受精。
Other treatments will become available sooner.
另一種療法也將很快得到應用。
OvaScience, a fertility company based in Boston which has exclusive rights to exploit Dr Tilly’s research on mammalian ovarian stem cells, will begin offering a novel treatment in July.
波士頓的OvaScience公司獨家開發Tilly博士的哺乳動物卵巢干細胞細胞研究。
This uses a woman’s own stem cells to provide her eggs with extra energy by creating fresh mitochondria—sub-units that exist within cells and supply them with energy.
今年7月，該公司將開始提供一種全新的療法：使用卵巢干細胞制造線粒體，給婦女的卵細胞增添活力。
They too can become scarcer and less productive with age.
線粒體的數量和活力也會隨著年齡增長而遞減。
Previous studies have shown that boosting mitochondria can dramatically increase the success rates of IVF.
此前的研究表明，增加線粒體數量能極大提高體外受精的成功率。
When it comes to reproduction, men will still have it easier for some time.
談起繁衍來，男人還能優哉游哉一陣子。
But women are catching up.
不過，女人即將迎頭趕上。
