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VOA慢速英语[科技报道]人类胚胎基因修复可以去除疾病

2017-08-14    来源:VOA    【      美国外教 在线口语培训

 

VOA慢速英语
 
2017-08-14

First Human Embryo Gene-Fix Could Help Stop Disease

Scientists in Oregon successfully fixed a disease-carrying gene in human embryos. It was the first time this has been done.

This small effort could be a big step in preventing inherited, or gene-related diseases.

A research team at Oregon Health & Science University edited out a gene that causes a heart problem and kills young people. Their work was published in the journal Nature.

Dr. Paula Amato is one of the scientists who worked on the study. She explained how it happened.

The team used sperm from a man who carries the heart-damaging gene. They injected his sperm into eggs, and at the same time injected a gene-editing tool called CRISPR-Cas-9. The CRISPR acts like scissors - cutting out the defective DNA.

What happened next is surprising: The embryos then fixed the DNA themselves, replacing the damaged part, without more help from the scientists.
 

 

VOA慢速

Amato says the gene defect correction rate was high, about 70% of the time. She says their success is proof that it can be done.

“It's very preliminary at this point but the potential is huge. But obviously much more research needs to be done before it moves to clinical trials.”

With 10,000 gene defects that cause disease, there would be no shortage of ones that could be fixed. But scientists are a long way from knowing how this would affect a baby.

“The biggest thing is safety. We don't know if this truly would be safe in, if we ever tried it to establish a pregnancy and produce a baby. But that’s [the] biggest ethical concern in my mind.”

The effect of editing genes

It is not known how permanently changing the genes may affect the following generations. Changing genes may produce children that are sick, much like the sheep Dolly. She was cloned in 1996—made from a genetic copy of another sheep—but she grew sick and died early.

Caplan says history tells us to wait and see how the technique works in animals first.
 

 

VOA慢速

“Let’s see how they turn out after a few years and then we'll start to get excited about using this technology to really prevent disease in people. Then we can really argue about whether it’s better to screen the embryos and throw them away or fix them.”


The U.S. is not alone in doing this scientific research. Caplan says other countries like China, Britain and Singapore are also editing, or planning to edit, genes.

Like Harvard’s Dr. Daley, Caplan is calling for a group of scientists, ethicists, lawyers and others to create rules and observe the work of scientists editing genes. The rule making should come from the private groups, he says, not the government.

I’m Anne Ball.

Anne Ball wrote this story for Learning English with information from the Associated Press. Hai Do was the editor. We want to hear from you. Write to us in the Comments Section and visit us on our Facebook page.

What do you think of the idea of editing, or permanently changing, genes?

Words in This Story


edit – v. to make changes, correct mistakes, etc., in something

defect – n. a problem or fault that makes someone or something not perfect

preliminary – adj. coming before the main part of something

ethics – n. rules of behavior based on ideas about what is morally good and bad

devastating – adj. causing great damage or harm

affirm – v. to say that something is true in a confident way

enhance – v. to increase or improve (something)

evolution – n. the process by which changes in plants and animals happen over time

in vitro fertilization - n. fertilization of an egg in a laboratory dish or test tube

plague – v. to cause constant or repeated trouble, illness, etc.,
 

 

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