2015考研英语阅读人类繁衍

　　Human reproduction

　　人类繁衍

　　Life begins at 45

　　45岁也能生娃

　　Hope for older mothers

　　高龄母亲的福音

　　WHEN it comes to reproduction, men have it easy.

　　讲到繁衍，男人表示压力很小。

　　Almost to the end of their lives most have an ample supply of sperm.

　　大多数人直到去世前都拥有充足的精子。

　　Women are not so lucky.

　　女人可就没这么幸运了。

　　They are born with a supply of eggs that typically runs out when they reach middle age.

　　人到中年，她们就会耗尽出生时携带的卵子。

　　That could be about to change, however.

　　不过，这一情形很快就能得到改变。

　　Researchers have confirmed that women harbour ovarian stem cells, and that these cangive rise to new eggs.

　　研究者们证实，女人拥有卵巢干细胞，而这种细胞能成为新的卵细胞的来源。

　　Stem cells have the ability to divide continuously and to change into different types of cells.

　　干细胞具有不断分裂的潜力，可以分化成许多种类的细胞。

　　Stem cells from adults can produce a variety of cell types, in addition to those that makeup the tissue in which they are found.

　　成人干细胞不仅可以分化成其来源组织的细胞，还能分化成其它细胞。

　　In 2004 Jonathan Tilly of Harvard Medical School and his colleagues discovered stem cells inmouse ovaries.

　　2004年，哈弗医学院的Jonathan Tilly及其同事在老鼠卵巢里发现了干细胞。

　　Since then it has been shown thatthese ovarian stem cells can develop into eggs, be fertilised and produce perfectly healthymouse pups.

　　迄今已经证实，此类卵巢干细胞能够分化成为卵细胞，卵细胞在受精后还能发育成健康的鼠宝宝。

　　But researchers have been reluctant to believe that something similar might be possible inhumans.

　　但是研究者尚不能确信人类也存在类似机能。

　　Proving that this was indeed the case was tricky.

　　想要弄清真相有些困难。

　　Human ovarian tissueespecially from young, healthy donorsis not easy to come by.

　　人类卵巢组织很难找到，健康的年轻捐献者的组织更难寻觅。

　　Dr Tillys breakthrough came when he discovered that a former colleague, Yasushi Takaiof Saitama Medical University in Japan, had in his freezer healthy ovarian tissue from 30patients who had changed sex.

　　幸而Tilly博士发现他的前同事日本埼玉医科大学的Yasushi Takai在冰箱里存放了30个变性人不再需要的健康卵巢组织，取得了突破。

　　Using a sophisticated cell-sorting technique, the researchers developed a way to identifyovarian stem cells that works for both mice and humans.

　　研究人员运用尖端的细胞分选技术，找出方法，证实人类和老鼠身上都存在卵巢干细胞。

　　Then they took the human ovarian stem cells, labelled them with a green fluorescentprotein and put them back into a slice of human ovary.

　　随后，他们分离出人类卵巢干细胞，用荧光蛋白做上标记再把它植入一片人类卵巢组织。

　　The glowing green cells soon produced a brand new crop of human eggs, according to theirfindings published this week in Nature Medicine.

　　这片组织被移植到了活鼠体内，使其保持正常卵巢的机能。他们本周发表在《自然医学》上的结果称，这些绿芒闪烁的细胞很快制造出了一批人类卵细胞。

　　Offshoring fertilisation

　　国外受精

　　Fertilising these eggs for experimentation is forbidden in America.

　　美国禁止为实验用的卵细胞受精，

　　Britains Human Fertilisation and Embryology Authority, however, will allow it in certaincases.

　　不过英国的人类受精和胚胎学管理局将在某些研究中允许给卵细胞授精。

　　So next month Dr Tilly will take some of his stem cell booty to Edinburgh to collaborate withEvelyn Telfer, who has developed a technique for growing human eggs from an early stage.

　　所以，下个月Tilly博士将带着卵细胞去爱丁堡与Evelyn Telfer合作。Evelyn Telfer掌握了用卵母细胞培育卵细胞的技术，

　　She holds a licence to fertilise them experimentally.

　　持有给试验用细胞授精的许可。

　　The discovery could revolutionise infertility treatment for women in several ways.

　　这项发现会是女性不育症治疗的一场革命。

　　For one thing, research has shown that in mice, even aged ovaries contain ovarian stemcells.

　　一方面，老鼠体内衰老的卵巢里也有卵巢干细胞;

　　And when those stem cells are placed into a young ovary, they will develop healthy eggs.

　　将这些细胞移植到年轻的卵巢中后，它们能制造健康的卵子。

　　This raises the possibility that, one day, women of advanced age could have their ownbiologically related children.

　　这意味着将来的某天，年龄较大的妇女也能拥有生物学意义上的自己的孩子。

　　Currently, many women over 45 have to make do with in-vitro fertilisation using the egg of ayounger woman.

　　目前，许多45岁以上的妇女只能凑合着用年轻女人的卵细胞进行体外受精。

　　Other treatments will become available sooner.

　　另一种疗法也将很快得到应用。

　　OvaScience, a fertility company based in Boston which has exclusive rights to exploit DrTillys research on mammalian ovarian stem cells, will begin offering a novel treatment inJuly.

　　波士顿的OvaScience公司独家开发Tilly博士的哺乳动物卵巢干细胞细胞研究。

　　This uses a womans own stem cells to provide her eggs with extra energy by creating freshmitochondriasub-units that exist within cells and supply them with energy.

　　今年7月，该公司将开始提供一种全新的疗法：使用卵巢干细胞制造线粒体，给妇女的卵细胞增添活力。

　　They too can become scarcer and less productive with age.

　　线粒体的数量和活力也会随着年龄增长而递减。

　　Previous studies have shown that boosting mitochondria can dramatically increase the successrates of IVF.

　　此前的研究表明，增加线粒体数量能极大提高体外受精的成功率。

　　When it comes to reproduction, men will still have it easier for some time.

　　谈起繁衍来，男人还能优哉游哉一阵子。

　　But women are catching up.

　　不过，女人即将迎头赶上。

　　词语解释

　　1.reproduction n.再现;复制;生殖

　　Her description of the meeting is an exactreproduction of the reunion.

　　她对会面的描述是这次团聚的真实再现。

　　2.supply v.供应;提供;补充

　　They wrote off for a fresh supply of penicillin.

　　他们发信要求再供应一批青霉素。

　　3.ovarian a.卵巢的

　　Ovarian cancer is a malignant tumour in the ovary.

　　卵巢癌是生长在卵巢的恶性肿瘤。

　　4.fertilise v.施肥于;使肥沃;使受精

　　Flowers are often fertilized by bees as they gather nectar.

　　蜜蜂采蜜时常使花受粉。

　　5.reluctant a.不情愿的;勉强的

　　I was reluctant to do over the stitching in the dress.

　　我不愿意把衣服上的线脚拆了重缝。