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科学美国人60秒 SSS Water Bears' Super Survival Skills Give Up Secrets

时间:2017-03-06 03:02:36

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(单词翻译)

 

Forget cockroaches1. Forget Superman. Forget any other tough-as-nails creatures you’ve ever heard of. The most indestructible multicellular organisms on Earth are undoubtedly3 tardigrades—microscopic eight-legged aquatic4 invertebrates5 also known as water bears.

These wee beasties can withstand severe dehydration6, extreme temperatures and pressures, several days in Earth orbit exposed to the vacuum of space, and whopping doses of radiation that would kill most anything else. And, being Earthlings, there’s no reason to think they’d be vulnerable to kryptonite.

Scientists are beginning to understand the genetic8 basis of tardigrades’ death-defying superpowers. And what they’re learning may have profound implications for human health.

The genome for a species of tardigrade was first sequenced last year. The analysis suggested that about one-sixth of the DNA9 was imported from notoriously hard-to-kill bacteria—but that conclusion was soon disputed, with all that bacterial10 DNA blamed on laboratory contamination.

Now, a new genome has been published of an exceptionally hardy11 tardigrade species. And it finds that almost all of the DNA is homegrown—and chock-full of sequences responsible for cellular2 protection and repair. The study is in the journal Nature Communications. [Takuma Hashimoto et al., Extremotolerant tardigrade genome and improved radiotolerance of human cultured cells by tardigrade-unique protein]

In particular, the researchers discovered the gene7 for a protein apparently13 unique to water bears that shields their DNA from radiation damage. Called “DSup” for “damage suppressor,” the protein binds14 to tardigrade DNA to keep it from snapping apart when bombarded by x-rays and other harsh radiation. The protein’s protective effects against radiation may be a by-product15 of the tardigrades’ resistance to dehydration, which causes similar damage to cells.

The most remarkable16 thing about the Dsup protein, though, is that it also seems to work in other organisms—including humans. When the researchers inserted Dsup into cultured human kidney cells, the protein boosted the cells’ tolerance12 to x-ray damage by about 40 percent.

In theory, Dsup or something much like it could protect workers at nuclear power plants, cancer patients receiving radiation therapy or astronauts on interplanetary voyages. For now, the ethics17 and practicality of genetic engineering make such applications highly speculative18. But, just maybe, if human beings someday stand on the surface of Mars, they could have water bear DNA to thank for helping19 them survive.

—Lee Billings


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1 cockroaches 1936d5f0f3d8e13fc00370b7ef69c14c     
n.蟑螂( cockroach的名词复数 )
参考例句:
  • At night, the cockroaches filled the house with their rustlings. 夜里,屋里尽是蟑螂窸窸瑟瑟的声音。 来自辞典例句
  • It loves cockroaches, and can keep a house clear of these hated insects. 它们好食蟑螂,可以使住宅免除这些讨厌昆虫的骚扰。 来自百科语句
2 cellular aU1yo     
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。
3 undoubtedly Mfjz6l     
adv.确实地,无疑地
参考例句:
  • It is undoubtedly she who has said that.这话明明是她说的。
  • He is undoubtedly the pride of China.毫无疑问他是中国的骄傲。
4 aquatic mvXzk     
adj.水生的,水栖的
参考例句:
  • Aquatic sports include swimming and rowing.水上运动包括游泳和划船。
  • We visited an aquatic city in Italy.我们在意大利访问过一个水上城市。
5 invertebrates 7e45dc289993d00de9b9f14a70e51319     
n.无脊椎动物( invertebrate的名词复数 )
参考例句:
  • Insects and worms are all invertebrates. 昆虫和蠕虫都是无脊椎动物。 来自辞典例句
  • In the earthworm and many other invertebrates, these excretory structures are called nephridia. 在蚯蚓和许多其它无脊椎动物中,这些排泄结构称为肾管。 来自辞典例句
6 dehydration UYkzX     
n.脱水,干燥
参考例句:
  • He died from severe dehydration.他死于严重脱水。
  • The eyes are often retracted from dehydration.眼睛常因脱水而凹陷。
7 gene WgKxx     
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。
8 genetic PgIxp     
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。
9 DNA 4u3z1l     
(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。
10 bacterial dy5z8q     
a.细菌的
参考例句:
  • Bacterial reproduction is accelerated in weightless space. 在失重的空间,细菌繁殖加快了。
  • Brain lesions can be caused by bacterial infections. 大脑损伤可能由细菌感染引起。
11 hardy EenxM     
adj.勇敢的,果断的,吃苦的;耐寒的
参考例句:
  • The kind of plant is a hardy annual.这种植物是耐寒的一年生植物。
  • He is a hardy person.他是一个能吃苦耐劳的人。
12 tolerance Lnswz     
n.宽容;容忍,忍受;耐药力;公差
参考例句:
  • Tolerance is one of his strengths.宽容是他的一个优点。
  • Human beings have limited tolerance of noise.人类对噪音的忍耐力有限。
13 apparently tMmyQ     
adv.显然地;表面上,似乎
参考例句:
  • An apparently blind alley leads suddenly into an open space.山穷水尽,豁然开朗。
  • He was apparently much surprised at the news.他对那个消息显然感到十分惊异。
14 binds c1d4f6440575ef07da0adc7e8adbb66c     
v.约束( bind的第三人称单数 );装订;捆绑;(用长布条)缠绕
参考例句:
  • Frost binds the soil. 霜使土壤凝结。 来自《简明英汉词典》
  • Stones and cement binds strongly. 石头和水泥凝固得很牢。 来自《简明英汉词典》
15 by-product nSayP     
n.副产品,附带产生的结果
参考例句:
  • Freedom is the by-product of economic surplus.自由是经济盈余的副产品。
  • The raw material for the tyre is a by-product of petrol refining.制造轮胎的原材料是提炼汽油时产生的一种副产品。
16 remarkable 8Vbx6     
adj.显著的,异常的,非凡的,值得注意的
参考例句:
  • She has made remarkable headway in her writing skills.她在写作技巧方面有了长足进步。
  • These cars are remarkable for the quietness of their engines.这些汽车因发动机没有噪音而不同凡响。
17 ethics Dt3zbI     
n.伦理学;伦理观,道德标准
参考例句:
  • The ethics of his profession don't permit him to do that.他的职业道德不允许他那样做。
  • Personal ethics and professional ethics sometimes conflict.个人道德和职业道德有时会相互抵触。
18 speculative uvjwd     
adj.思索性的,暝想性的,推理的
参考例句:
  • Much of our information is speculative.我们的许多信息是带推测性的。
  • The report is highly speculative and should be ignored.那个报道推测的成分很大,不应理会。
19 helping 2rGzDc     
n.食物的一份&adj.帮助人的,辅助的
参考例句:
  • The poor children regularly pony up for a second helping of my hamburger. 那些可怜的孩子们总是要求我把我的汉堡包再给他们一份。
  • By doing this, they may at times be helping to restore competition. 这样一来, 他在某些时候,有助于竞争的加强。

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