英语听力：自然百科 探索世界奥秘之The Ghost In Your Genes(基因外遗传现象) Unit07

探索世界奥秘之The Ghost In Your Genes²(基因外遗传现象) Unit07

After we had seen how relatively³ easy it was to change the switches in mouse embryos⁵, we thought that perhaps the same could be true of human embryos. In IVF, you also have the embryo⁴ for a brief period of time in a culture dish. And so we were asking the question whether as in a mouse embryo, the mere⁶ fact of human embryos having been in a culture dish, or been manipulated, could alter their epigenetic switches?

Wolf knew that Beckwith-Wiedemann syndrome⁷ was caused by a faulty switch.

So what we were looking at was a group of babies and children that have the Beckwith-Wiedemann syndrome. What proportion of those were conceived by, by IVF.

Could IVF be switching genes on or off? Could IVF itself cause the syndrome?

What we found was an increased occurrence of this epigenetic syndrome in the IVF population.

Although the disease is extremely rare, the risk appeared to increase three to four times with IVF. It seemed that the simple act of removing the embryo from its natural environment could trigger the disease.

And, I do feel frustrated⁸ that Karen might possibly have Beckwith-Wiedemann syndrome as the, because we had IVF. But at the time, it was the right decision to make.

And I think that we should look again at the IVF procedures, the conditions that are being used and carry out better and more precise experiments to see how we can avoid throwing these epigenetic switches.

Wolf had shown a simple change in environment was enough to turn a gene¹ on or off. But there was more. Everyone thought that any altered switches could not be inherited. He took some mice with altered gene switches and bred them.

Our expectation was that as the altered genome was passed to the children that any epigenetic changes would be wiped clean.

When he looked at the gene profile of the offspring, he was amazed.

You have dots that you were looking at, and every dot means a gene is on. And all of a sudden, you know, somebody said, "Wow, Look at that".

The epigenetic switch thrown in one generation was clearly also present in the second generation.

1 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。

2 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

3 relatively   

adv.比较...地，相对地

参考例句：

• The rabbit is a relatively recent introduction in Australia.兔子是相对较新引入澳大利亚的物种。
• The operation was relatively painless.手术相对来说不痛。

4 embryo   

n.胚胎，萌芽的事物

参考例句：

• They are engaging in an embryo research.他们正在进行一项胚胎研究。
• The project was barely in embryo.该计划只是个雏形。

5 embryos   

n.晶胚；胚，胚胎( embryo的名词复数 )

参考例句：

• Somatic cells of angiosperms enter a regenerative phase and behave like embryos. 被子植物体细胞进入一个生殖阶段，而且其行为象胚。 来自辞典例句
• Evolution can explain why human embryos look like gilled fishes. 进化论能够解释为什么人类的胚胎看起来象除去了内脏的鱼一样。 来自辞典例句

6 mere   

adj.纯粹的；仅仅，只不过

参考例句：

• That is a mere repetition of what you said before.那不过是重复了你以前讲的话。
• It's a mere waste of time waiting any longer.再等下去纯粹是浪费时间。

7 syndrome   

n.综合病症；并存特性

参考例句：

• The Institute says that an unidentified virus is to blame for the syndrome. 该研究所表示,引起这种综合症的是一种尚未确认的病毒。
• Results indicated that 11 fetuses had Down syndrome. 结果表明有11个胎儿患有唐氏综合征。

8 frustrated   

adj.挫败的，失意的，泄气的v.使不成功( frustrate的过去式和过去分词 )；挫败；使受挫折；令人沮丧

参考例句：

• It's very easy to get frustrated in this job. 这个工作很容易令人懊恼。
• The bad weather frustrated all our hopes of going out. 恶劣的天气破坏了我们出行的愿望。 来自《简明英汉词典》