科学美国人60秒 SSS Water Bears' Super Survival Skills Give Up Secrets
时间：2019-01-17 作者：英语课 分类：2016年Scientific American(十)月
Forget cockroaches 1. Forget Superman. Forget any other tough-as-nails creatures you’ve ever heard of. The most indestructible multicellular organisms on Earth are undoubtedly 3 tardigrades—microscopic eight-legged aquatic 4 invertebrates 5 also known as water bears.
These wee beasties can withstand severe dehydration 6, 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 genetic 8 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 DNA 9 was imported from notoriously hard-to-kill bacteria—but that conclusion was soon disputed, with all that bacterial 10 DNA blamed on laboratory contamination.
Now, a new genome has been published of an exceptionally hardy 11 tardigrade species. And it finds that almost all of the DNA is homegrown—and chock-full of sequences responsible for cellular 2 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 gene 7 for a protein apparently 13 unique to water bears that shields their DNA from radiation damage. Called “DSup” for “damage suppressor,” the protein binds 14 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-product 15 of the tardigrades’ resistance to dehydration, which causes similar damage to cells.
The most remarkable 16 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’ tolerance 12 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 ethics 17 and practicality of genetic engineering make such applications highly speculative 18. But, just maybe, if human beings someday stand on the surface of Mars, they could have water bear DNA to thank for helping 19 them survive.
—Lee Billings
- 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
- 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。
- 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。
- 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。
- 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
- 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。
- 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。
- 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。
- 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。
- 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。
- 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。
- 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。
- 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。
- 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》
- 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。
- 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。
- 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。
- 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。