英语沙龙：克隆人类也许更容易

Cloning Humans May Have It Easier

Most scientists agreed that cloning an entire human being －－besides being morally question－able －－was fraught¹ with technical obstacles．After all，research into animal cloning has already shown that there are hundreds of failures，including many badly deformed² creatures that were usually miscarried．

Now comes word that it might be easier to clone humans than was previously³ believed．People have a genetic⁵ quirk⁶ that might pr event some of the developmental deformities associated with animal cloning．One gene⁴，called IGF2R，is normally imprinted⁷ in sheep，cows and mice but not in humans．Human clones would always inherit nonimprinted IGF2R genes⁸，so t here would be no chance of a mix－up and，their growth would be normal．But what of the other 49or so imprinted genes？No one knows what trouble they might cause．So the fact that humans have one less imprinted gene than mice，sheep or cows means that human cloning might be marginally easier，but not necessarily safer．

克隆人类也许更容易

许多科学家都认为克隆一个完整的人---除了在伦理上令人怀疑外---还存有许多技术障碍。毕竟，对动物克隆的深入研究已经表明有上百个失败案例，包括许多因严重畸形而通常流产的动物。

现在有消息说克隆人可能比以前所认为的要容易。人类有一种基因突变可以防止一些与动物克隆相关的发育畸形。一种叫做IGF２R的基因，通常遗传到绵羊、奶牛和老鼠，但不在人类身上。人类克隆一直是继承非遗传性的IGF２R基因，所以不会造成混乱，他们的发育将是正常的。但是另外约49个遗传基因会怎样呢？没有人能够知道他们会造成什么样的麻烦。所以人类比老鼠、绵羊和奶牛少一个遗传基因这一事实意味着克隆人类可能稍容易一些，但并不一定更安全。

1 fraught   

adj.充满…的，伴有(危险等)的；忧虑的

参考例句：

• The coming months will be fraught with fateful decisions.未来数月将充满重大的决定。
• There's no need to look so fraught!用不着那么愁眉苦脸的！

2 deformed   

adj.畸形的；变形的；丑的，破相了的

参考例句：

• He was born with a deformed right leg.他出生时右腿畸形。
• His body was deformed by leprosy.他的身体因为麻风病变形了。

3 previously   

adv.以前，先前（地）

参考例句：

• The bicycle tyre blew out at a previously damaged point.自行车胎在以前损坏过的地方又爆开了。
• Let me digress for a moment and explain what had happened previously.让我岔开一会儿，解释原先发生了什么。

4 gene   

n.遗传因子，基因

参考例句：

• A single gene may have many effects.单一基因可能具有很多种效应。
• The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。

5 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

6 quirk   

n.奇事，巧合；古怪的举动

参考例句：

• He had a strange quirk of addressing his wife as Mrs Smith.他很怪，把自己的妻子称作史密斯夫人。
• The most annoying quirk of his is wearing a cap all the time.他最令人感到厌恶的怪癖就是无论何时都戴著帽子。

7 imprinted   

v.盖印（imprint的过去式与过去分词形式）

参考例句：

• The terrible scenes were indelibly imprinted on his mind. 那些恐怖场面深深地铭刻在他的心中。
• The scene was imprinted on my mind. 那个场面铭刻在我的心中。 来自《简明英汉词典》

8 genes   

n.基因( gene的名词复数 )

参考例句：

• You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因，所以能够活得很长。 来自《简明英汉词典》
• Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪