美国国家公共电台 NPR To Fight Malaria, Scientists Try Genetic Engineering To Wipe Out Mosquitoes

 

AUDIE CORNISH, HOST: 

What if scientists could genetically³ modify mosquitoes to wipe out a disease that kills hundreds of thousands of people each year? They're trying to do that with a new genetic² engineering technique. They hope it will help them fight some of the world's other big problems, too.

Now, there are fears about releasing insects made this way into the wild. NPR's health correspondent Rob Stein visited one of the first labs to engineer a living creature with this technology.

ROB STEIN, BYLINE⁴: What you're about to hear may just sound like static at first, but if you listen closely, you can hear them.

(SOUNDBITE OF MOSQUITOES BUZZING)

STEIN: Mosquitoes - hundreds of genetically modified mosquitoes.

(SOUNDBITE OF MOSQUITOES BUZZING)

STEIN: And not just any genetically modified mosquitos. These are some of the first living things engineered to do something that has long been considered taboo⁵ - spread their mutant genes⁶ fast, really fast and as far as they can. For my close encounter with these mosquitoes, I traveled to London and found Andrew Hammond. He's a genetic engineer at Imperial College London.

ANDREW HAMMOND: You want me to show you the insectary and where we do some of the work.

STEIN: That'd be fabulous⁷. Thanks.

The insectary is where Hammond keeps these new mosquitoes. He leads me to a highly secure elevator and takes me down five floors to the basement.

COMPUTER-GENERATED VOICE: Going down.

HAMMOND: There's a few layers of security to get down here.

STEIN: We pass through a series of heavy doors equipped with special blowers to push back any genetically modified mosquitoes that try to escape before finally arriving at the insectary. Even though outside London is cold and gray, in here, it's hot and humid like the tropics to keep the mosquitoes happy. Hammond picks up a small cage made out of white mosquito netting.

HAMMOND: Inside this cage, you've got the adult mosquitoes.

STEIN: What kind of mosquitoes are these?

HAMMOND: Everything in this cubicle⁸ is genetically modified.

STEIN: They look like regular mosquitoes, but they're not. They've had something new spliced⁹ into their genes, something known as a gene¹ drive, which is a sequence of DNA¹⁰ created in the lab that drives its way through the gene pool much faster than most genes. The research is funded by the Gates Foundation, which also supports NPR.

HAMMOND: These gene drives - they're able to copy themselves. So instead of half of the offspring inheriting the gene drive, almost all of them do.

STEIN: That's huge. Scientists have always tried to keep genetically engineered creatures from spreading their new DNA to keep them from messing up the natural world. A gene drive genetic modification¹¹ - it's designed to spread.

HAMMOND: So what happens is it spreads, and it spreads, and it spreads. And this is the fantastic thing because in a very short amount of time, you can actually transform an entire wild population into a modified population.

STEIN: Wow.

HAMMOND: Yeah, it's powerful.

STEIN: So powerful that Hammond and his colleagues think they can use their gene drive mosquitoes to do something humanity's been trying to do for decades - wipe out malaria¹² because these mosquitoes spread mutations designed to sterilize¹³ the mosquitoes that spread the malaria parasite¹⁴.

HAMMOND: And if we sterilize the females, you can actually eliminate a whole mosquito population without affecting those mosquitoes that don't have the capability¹⁵ to transmit malaria. It's fantastic.

STEIN: And that's just the beginning. Scientists think gene drives could let them do all sorts of things - eradicate¹⁶ other diseases spread by insects like Lyme disease and Zika, feed the world more safely by creating crops that don't need polluting pesticides¹⁷, save endangered species and entire ecosystems¹⁸. But critics worry gene drives are just too powerful.

RICARDA STEINBRECHER: It has huge implications. It's a tool that's never been in our hands before, and it's just a high-risk technology.

STEIN: Ricarda Steinbrecher is a scientist at the genetic watchdog group EcoNexus in Oxford¹⁹, England.

STEINBRECHER: You can have a collapse²⁰ of ecosystems. You can have more diseases arising. You can make the whole system fragile towards climatic conditions. It basically is an unknown we are dealing²¹ with here.

STEIN: Back in the lab, Andrew Hammond takes me to another area to show me how he creates gene drive mosquitoes.

HAMMOND: This is our microinjection facility. So this is what we use to actually make the transgenic mosquitoes.

STEIN: It's a big, dark room. Hammond sits down in front of a microscope and picks up a slide. It's got dozens of tiny black specks²³ on it. Each speck²² is a mosquito embryo²⁴. Hammond lets me take a quick peek²⁵ under the microscope. Each embryo looks like a big black blob. A thin glass needle is pointing at one of the blobs.

HAMMOND: Inside this needle is a solution that contains the DNA. And we're going to use this to modify the genome and integrate into it our gene drive.

STEIN: To integrate the gene drive, Hammond's using a new DNA editing technique called CRISPR that's revolutionizing genetic engineering by making it way easier and faster. It's letting scientists like Hammond harness the power of gene drives.

(SOUNDBITE OF ELECTRIC MOTOR)

STEIN: That sound...

HAMMOND: That sound is manipulating this needle into the right place.

STEIN: Hammond has less than an hour to edit as many embryos²⁶ as he can before they dry out.

HAMMOND: Need to be very quick when you put the needle inside, and you need to inject just the right amount of DNA. Too much will kill it, and too little won't modify it. But if you place it in and inject - there, that's done.

STEIN: And that's how you edit the DNA in a mosquito embryo.

HAMMOND: That's right.

STEIN: After they're edited, Hammond lets the embryos mature and mate with normal mosquitoes then examines their larva under another microscope that lights them up with a laser. The modified mosquitoes also get a marker that makes their eyes and other parts of their bodies glow if the gene drive is working.

HAMMOND: When I look at them, if I see that half of them are red, then our gene drive is not working. But if we see that almost all of them are red, then it's definitely working.

STEIN: And what are you seeing?

HAMMOND: That it's definitely working (laughter).

STEIN: He shows me one of the gene drive mosquito larva magnified on a screen. It looks like something out of a horror film, like a huge radioactive worm.

HAMMOND: We can see it glowing up in the eyes and glowing down the body. It's beautiful.

STEIN: Why do you call it beautiful?

HAMMOND: Just these incredible patterns that are formed by the neurons and the bright red fluorescence. I mean it's a stunning²⁷ image - beautiful scientifically and beautiful visually.

STEIN: But not everyone thinks this is so beautiful. Critics find it frightening. They say there's no way to know what gene drive creatures might do if they're ever let loose. They could mutate, unleash²⁸ new epidemics²⁹, cause famines. And Jim Thomas of the genetic watchdog the ETC Group says that's not all.

JIM THOMAS: This potentially could be a way of creating some quite nasty bio weapons. You could engineer an insect - stinging insect, for example, to deliver a toxin³⁰. Mosquitoes would be an obvious possible target. That would be a way that you could weaponize this technology. That certainly is of concern.

STEIN: Andrew Hammond and his colleagues doubt gene drives would ever be used that way, and they argue the potential benefits are so huge that they have to try to find a way to use them safely. Molecular³¹ biologist Tony Nolan is Hammond's boss.

TONY NOLAN: We don't work in an ivory tower. We are fully³² aware of people's concerns on this. I think that we've got to weigh up the benefits whenever you consider risk. And I think that given that there are still half a million people dying, most of them children, from malaria, I think it's a worthwhile goal to investigate this technology.

STEIN: But Nolan acknowledges that gene drives could be dangerous and be misused³³, so he and his colleagues are planning years of careful testing to make sure their mosquitoes are safe before they try to convince any countries to let them release them into the wild.

Meanwhile, other scientists, along with the U.S. military, are trying to develop antidotes³⁴ to gene drive modifications³⁵ just in case one does run amok someday. Rob Stein, NPR News, London.

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 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。

3 genetically   

adv.遗传上

参考例句：

• All the bees in the colony are genetically related. 同一群体的蜜蜂都有亲缘关系。
• Genetically modified foods have already arrived on American dinner tables. 经基因改造加工过的食物已端上了美国人的餐桌。 来自英汉非文学 - 生命科学 - 基因与食物

4 byline   

n.署名；v.署名

参考例句：

• His byline was absent as well.他的署名也不见了。
• We wish to thank the author of this article which carries no byline.我们要感谢这篇文章的那位没有署名的作者。

5 taboo   

n.禁忌，禁止接近，禁止使用；adj.禁忌的；v.禁忌，禁制，禁止

参考例句：

• The rude words are taboo in ordinary conversation.这些粗野的字眼在日常谈话中是禁忌的。
• Is there a taboo against sex before marriage in your society?在你们的社会里，婚前的性行为犯禁吗？

6 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

7 fabulous   

adj.极好的；极为巨大的；寓言中的，传说中的

参考例句：

• We had a fabulous time at the party.我们在晚会上玩得很痛快。
• This is a fabulous sum of money.这是一笔巨款。

8 cubicle   

n.大房间中隔出的小室

参考例句：

• She studies in a cubicle in the school library.她在学校图书馆的小自习室里学习。
• A technical sergeant hunches in a cubicle.一位技术军士在一间小屋里弯腰坐着。

9 spliced   

adj.（针织品）加固的n.叠接v.绞接( splice的过去式和过去分词 )；捻接（两段绳子）；胶接；粘接（胶片、磁带等）

参考例句：

• He spliced the two lengths of film together. 他把两段胶卷粘接起来。 来自《简明英汉词典》
• Have you heard?John's just got spliced. 听说了吗？约翰刚结了婚。 来自辞典例句

10 DNA   

(缩)deoxyribonucleic acid 脱氧核糖核酸

参考例句：

• DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
• Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。

11 modification   

n.修改，改进，缓和，减轻

参考例句：

• The law,in its present form,is unjust;it needs modification.现行的法律是不公正的，它需要修改。
• The design requires considerable modification.这个设计需要作大的修改。

12 malaria   

n.疟疾

参考例句：

• He had frequent attacks of malaria.他常患疟疾。
• Malaria is a kind of serious malady.疟疾是一种严重的疾病。

13 sterilize   

vt.使不结果实；使绝育；使无效；杀菌，消毒

参考例句：

• Antiseptic is used to sterilize the skin before giving an injection.杀菌剂被用于在注射前给皮肤消毒。
• He pricks the blister on his heel with a sterilize needle.他用一根消过毒的针扎破他脚后跟上的水泡。

14 parasite   

n.寄生虫；寄生菌；食客

参考例句：

• The lazy man was a parasite on his family.那懒汉是家里的寄生虫。
• I don't want to be a parasite.I must earn my own way in life.我不想做寄生虫，我要自己养活自己。

15 capability   

n.能力；才能；(pl)可发展的能力或特性等

参考例句：

• She has the capability to become a very fine actress.她有潜力成为杰出演员。
• Organizing a whole department is beyond his capability.组织整个部门是他能力以外的事。

16 eradicate   

v.根除，消灭，杜绝

参考例句：

• These insects are very difficult to eradicate.这些昆虫很难根除。
• They are already battling to eradicate illnesses such as malaria and tetanus.他们已经在努力消灭疟疾、破伤风等疾病。

17 pesticides   

n.杀虫剂( pesticide的名词复数 )；除害药物

参考例句：

• vegetables grown without the use of pesticides 未用杀虫剂种植的蔬菜
• There is a lot of concern over the amount of herbicides and pesticides used in farming. 人们对农业上灭草剂和杀虫剂的用量非常担忧。 来自《简明英汉词典》

18 ecosystems   

n.生态系统( ecosystem的名词复数 )

参考例句：

• There are highly sensitive and delicately balanced ecosystems in the forest. 森林里有高度敏感、灵敏平衡的各种生态系统。 来自《简明英汉词典》
• Madagascar's ecosystems range from rainforest to semi-desert. 马达加斯加生态系统类型多样，从雨林到半荒漠等不一而足。 来自辞典例句

19 Oxford   

n.牛津（英国城市）

参考例句：

• At present he has become a Professor of Chemistry at Oxford.他现在已是牛津大学的化学教授了。
• This is where the road to Oxford joins the road to London.这是去牛津的路与去伦敦的路的汇合处。

20 collapse   

vi.累倒；昏倒；倒塌；塌陷

参考例句：

• The country's economy is on the verge of collapse.国家的经济已到了崩溃的边缘。
• The engineer made a complete diagnosis of the bridge's collapse.工程师对桥的倒塌做了一次彻底的调查分析。

21 dealing   

n.经商方法，待人态度

参考例句：

• This store has an excellent reputation for fair dealing.该商店因买卖公道而享有极高的声誉。
• His fair dealing earned our confidence.他的诚实的行为获得我们的信任。

22 speck   

n.微粒，小污点，小斑点

参考例句：

• I have not a speck of interest in it.我对它没有任何兴趣。
• The sky is clear and bright without a speck of cloud.天空晴朗，一星星云彩也没有。

23 specks   

n.眼镜；斑点，微粒，污点( speck的名词复数 )

参考例句：

• Minutes later Brown spotted two specks in the ocean. 几分钟后布朗发现海洋中有两个小点。 来自英汉非文学 - 百科语料821
• Do you ever seem to see specks in front of your eyes? 你眼睛前面曾似乎看见过小点吗？ 来自辞典例句

24 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。

25 peek   

vi.偷看，窥视；n.偷偷的一看，一瞥

参考例句：

• Larry takes a peek out of the window.赖瑞往窗外偷看了一下。
• Cover your eyes and don't peek.捂上眼睛，别偷看。

26 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

27 stunning   

adj.极好的；使人晕倒的

参考例句：

• His plays are distinguished only by their stunning mediocrity.他的戏剧与众不同之处就是平凡得出奇。
• The finished effect was absolutely stunning.完工后的效果非常美。

28 unleash   

vt.发泄，发出；解带子放开

参考例句：

• They hope to create allies to unleash against diseases,pests,and invasive species.他们希望创造出一些新群体来对付疾病、害虫和一些有侵害性的物种。
• Changing water levels now at times unleash a miasma of disease from exposed sewage.如今，大坝不时地改变水位，从暴露的污水释放出了疾病瘴气。

29 epidemics   

n．流行病

参考例句：

• Reliance upon natural epidemics may be both time-consuming and misleading. 依靠天然的流行既浪费时间，又会引入歧途。
• The antibiotic epidemics usually start stop when the summer rainy season begins. 传染病通常会在夏天的雨季停止传播。

30 toxin   

n.毒素，毒质

参考例句：

• Experts have linked this condition to a build-up of toxins in the body.专家已把这一病症与体内毒素的积累联系起来。
• Tests showed increased levels of toxin in shellfish.检验表明水生有壳动物的毒素水平提高了。

31 molecular   

adj.分子的；克分子的

参考例句：

• The research will provide direct insight into molecular mechanisms.这项研究将使人能够直接地了解分子的机理。
• For the pressure to become zero, molecular bombardment must cease.当压强趋近于零时，分子的碰撞就停止了。

32 fully   

adv.完全地，全部地，彻底地；充分地

参考例句：

• The doctor asked me to breathe in,then to breathe out fully.医生让我先吸气，然后全部呼出。
• They soon became fully integrated into the local community.他们很快就完全融入了当地人的圈子。

33 misused   

v.使用…不当( misuse的过去式和过去分词 )；把…派作不正当的用途；虐待；滥用

参考例句：

• He misused his dog shamefully. 他可耻地虐待自己的狗。 来自《简明英汉词典》
• He had grossly misused his power. 他严重滥用职权。 来自《简明英汉词典》

34 antidotes   

解药( antidote的名词复数 )； 解毒剂； 对抗手段； 除害物

参考例句：

• Treatment involves giving antidotes that Bind the lead in the tissues. 治疗办法有用解毒剂，它会与组织中的铅结合而把它驱逐出去。
• With Spleen Qi, heat antidotes, such as cough Runfei effectiveness. 具有补脾益气、清热解毒、润肺止咳等功效。

35 modifications   

n.缓和( modification的名词复数 )；限制；更改；改变

参考例句：

• The engine was pulled apart for modifications and then reassembled. 发动机被拆开改型，然后再组装起来。 来自《简明英汉词典》
• The original plan had undergone fairly extensive modifications. 原计划已经作了相当大的修改。 来自《简明英汉词典》