VOA慢速英语2020--中国科学家开发出延缓衰老的基因疗法

From VOA Learning English, this is the Health & Lifestyle report.

Scientists in Beijing, China have developed a new gene¹ therapy that can turn back some of the effects of aging in mice. The therapy also extended their lives. This may one day help humans as well.

The gene therapy involved disabling a gene called kat7. Scientists have found this gene to be the main cause of aging in cells.

Qu Jing of the Institute of Zoology² at the Chinese Academy of Sciences, or CAS, is one of the supervisors³ of the project. After six to eight months, Qu said, the mice showed an overall improvement in their appearance and grip strength. More importantly, she added, "they have (an) extended lifespan (of) about 25 percent."

A different team of scientists at the academy used a method called CRISPR/Cas9 to look for genes⁴ that cause the most cellular⁵ aging. They identified 100 genes out of around 10,000.

The kat7 gene, Qu said, was most involved in the aging of cells. It is one of tens of thousands of genes found in the cells of mammals.

Researchers disabled the kat7 gene in the livers of the mice in the study. They used a method called lentiviral vector to modify the gene by inserting a genetic⁶ material into the cell.

Their findings were published in the Science Translational Medicine paper in early January.

Qu said they tested the working of kat7 gene in different kinds of cell types, including human stem cells, human liver cells and mice liver cells. For all those cells, the researchers could not find any cellular toxicity⁷. "And for the mice, she added, "we also didn't see any side-effects yet."

Even with these findings, Qu told Reuters, the method to disable the kat7 gene is still a long way from being ready for human tests. She said they need more tests in other human cells and mice organs before experimenting the method on human aging and other health conditions.

Qu said she hopes to be able to test the method on primates¹⁰ next. But that would require a lot of money and much more research first.

"In the end," she said, "we hope that we can find a way to delay aging even by a very minor¹¹ percentage...in the future."

And that's the Health & Lifestyle report.

Words in This Story

gene therapy – science n. Gene therapy is an experimental technique that uses genes to treat or prevent disease.

grip – n. the act of grabbing or holding something

mammal – n. a type of animal that feeds milk to its young and that usually has hair or fur covering most of its skin

toxicity – medical n. the quality, state, or relative degree of being toxic⁸ or poisonous

primate⁹ – n. any member of the group of animals that includes human beings, apes, and monkeys

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 zoology   

n.动物学，生态

参考例句：

• I would like to brush up my zoology.我想重新温习一下动物学。
• The library didn't stock zoology textbooks.这家图书馆没有动物学教科书。

3 supervisors   

n.监督者，管理者( supervisor的名词复数 )

参考例句：

• I think the best technical people make the best supervisors. 我认为最好的技术人员可以成为最好的管理人员。 来自辞典例句
• Even the foremen or first-level supervisors have a staffing responsibility. 甚至领班或第一线的监督人员也有任用的责任。 来自辞典例句

4 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

5 cellular   

adj.移动的；细胞的，由细胞组成的

参考例句：

• She has a cellular telephone in her car.她的汽车里有一部无线通讯电话机。
• Many people use cellular materials as sensitive elements in hygrometers.很多人用蜂窝状的材料作为测量温度的传感元件。

6 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。

7 toxicity   

n.毒性，毒力

参考例句：

• The hoarse grunt or squeal is characteristic of toxicity.嘶哑的哼声和叫声是中毒的特征。
• Dieldrin is related to aldrin,and its toxicity to earthworms is similar.狄氏剂与艾氏剂有关，对蚯蚓的毒性是相似的。

8 toxic   

adj.有毒的，因中毒引起的

参考例句：

• The factory had accidentally released a quantity of toxic waste into the sea.这家工厂意外泄漏大量有毒废物到海中。
• There is a risk that toxic chemicals might be blasted into the atmosphere.爆炸后有毒化学物质可能会进入大气层。

9 primate   

n.灵长类（目）动物，首席主教；adj.首要的

参考例句：

• 14 percent of primate species are highly endangered.14%的灵长类物种处于高度濒危状态。
• The woolly spider monkey is the largest primate in the Americas.绒毛蛛猴是美洲最大的灵长类动物。

10 primates   

primate的复数

参考例句：

• Primates are alert, inquisitive animals. 灵长目动物是机灵、好奇的动物。
• Consciousness or cerebration has been said to have emerged in the evolution of higher primates. 据说意识或思考在较高级灵长类的进化中已出现。

11 minor   

adj.较小(少)的，较次要的；n.辅修学科；vi.辅修

参考例句：

• The young actor was given a minor part in the new play.年轻的男演员在这出新戏里被分派担任一个小角色。
• I gave him a minor share of my wealth.我把小部分财产给了他。