A step closer to 'synthetic life' “人造细胞”更进一步
文章来源:未知 文章作者:meng 发布时间:2009-08-21 02:32 字体: [ ]  进入论坛
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In what has been described as a step towards the creation of a synthetic1 cell, scientists have created a new "engineered" strain of bacteria.

科学家发现了一种新“设计”的细菌种类,在人造细胞创造的路程上进了一步。

The cells <a href=replicated2 to produce a new strain of Mycoplasma mycoides" width="226" border="0" src="/upimg/090821/4_025303_1.jpg" />
The cells replicated to produce a new strain of Mycoplasma mycoides

A team successfully transferred the genome(基因组) of one type of bacteria into a yeast4 cell(酵母细胞), modified it, and then transplanted into another bacterium5.

This paves the way to the creation of a synthetic(合成的,人造的) organism - inserting a human-made genome into a bacterial6 cell.

The team describe the work in the journal Science.

This advance, the researchers say, overcomes the obstacle of making a new inserted genome work inside a recipient7 cell.

The experiment was carried out by a team that included scientist J Craig Venter, a leading figure in the controversial field of synthetic biology.

Sanjay Vashee, a researcher at the J. Craig Venter Institute in Rockville, Maryland, in the US, was one of the authors.

The resulting cell he and his team created went on to undertake multiple rounds of cell division, to produce a new strain of the modified bacteria.

Dr Vashee explained to BBC News that the work overcame a hurdle8 in the quest to create a fully3 synthetic organism.

"Bacteria have 'immune' systems that protect them from foreign DNA9 such as those from viruses," he explained.

He and his colleagues managed to disable this immune system, which consists of proteins called restriction10 enzymes12(酵素) that home in on specific sections of DNA and chop up the genome at these points.

Bacteria can shield their own genomes from this process by attaching chemical compounds called methyl(甲基,木精) groups at the points which the restriction enzymes(限制酶) attack.

The scientists modified the original genome of the bacterium Mycoplasma mycoides, whilst it was inside the yeast cell. Then they either attached methyl groups to it, or inactivated13 the restriction enzyme11 of the recipient bacterium, before transplanting the genome into its new cell.

One of the team's ultimate aims is to transplant a fully synthetic genome into a bacterial cell - creating bacteria that can be programmed to carry out specific functions - for example, digesting biological material to produce fuel.

Race for life

Researchers at the same institute have already synthesised the complete genome of a bacterium they have called Mycoplasma genitalium(支原体). Dr Vashee described this work as a "logical extension" of that.

He told BBC News that attempts to create a synthetic bacterium by transplanting M. genitalium into a cell were "ongoing14".

"We have as of yet no conclusive15 proof that we have obtained M. genitalium cells after its genome has been put into various recipient(接受者,收信人) cells," he said.

"[But this] is a major advance in our effort to create a synthetic cell."

Dr Vashee continued: "We were very concerned that the differences between the modifications16 in... bacterial DNA and [yeast] DNA might be an insurmountable barrier(不可逾越的鸿沟), preventing transplantation into bacteria of genomes that were passed through yeast.

"Now we know how to do this."

Critics have expressed reservations about synthetic biology, and the aim to create what has been widely referred to as artificial life.

Many are concerned that the technology to engineer organisms could end up in the wrong hands.

Dr Vashee concluded: "Dr Venter and the team at JCVI continue to work with bioethicists, outside policy groups, [politicians], and the public to encourage discussion and understanding about the societal implications(蕴涵式) of their work and the field of synthetic genomics."



点击收听单词发音收听单词发音  

1 synthetic zHtzY     
adj.合成的,人工的;综合的;n.人工制品
参考例句:
  • We felt the salesman's synthetic friendliness.我们感觉到那位销售员的虚情假意。
  • It's a synthetic diamond.这是人造钻石。
2 replicated 08069c56938bbf6ddcc01ee2fd848af5     
复制( replicate的过去式和过去分词 ); 重复; 再造; 再生
参考例句:
  • Later outplant the seedlings in a replicated permanent test plantation. 以后苗木出圃栽植成重复的永久性试验林。
  • The phage has replicated and the donor cells have lysed. 噬菌体已复制和给体细胞已发生裂解。
3 fully Gfuzd     
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。
4 yeast 7VIzu     
n.酵母;酵母片;泡沫;v.发酵;起泡沫
参考例句:
  • Yeast can be used in making beer and bread.酵母可用于酿啤酒和发面包。
  • The yeast began to work.酵母开始发酵。
5 bacterium BN7zE     
n.(pl.)bacteria 细菌
参考例句:
  • The bacterium possibly goes in the human body by the mouth.细菌可能通过口进入人体。
  • A bacterium is identified as the cause for his duodenal ulcer.一种细菌被断定为造成他十二指肠溃疡的根源。
6 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。
7 recipient QA8zF     
a.接受的,感受性强的 n.接受者,感受者,容器
参考例句:
  • Please check that you have a valid email certificate for each recipient. 请检查是否对每个接收者都有有效的电子邮件证书。
  • Colombia is the biggest U . S aid recipient in Latin America. 哥伦比亚是美国在拉丁美洲最大的援助对象。
8 hurdle T5YyU     
n.跳栏,栏架;障碍,困难;vi.进行跨栏赛
参考例句:
  • The weather will be the biggest hurdle so I have to be ready.天气将会是最大的障碍,所以我必须要作好准备。
  • She clocked 11.6 seconds for the 80 metre hurdle.八十米跳栏赛跑她跑了十一秒六。
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 restriction jW8x0     
n.限制,约束
参考例句:
  • The park is open to the public without restriction.这个公园对公众开放,没有任何限制。
  • The 30 mph speed restriction applies in all built-up areas.每小时限速30英里适用于所有建筑物聚集区。
11 enzyme cPozF     
n.酵素,酶
参考例句:
  • Above a certain temperature,the enzyme molecule will become unfolded.超过一定温度,酶分子将会展开。
  • An enzyme that dissolves the fibrin of blood clots.能溶解血凝块中的纤维的酶。
12 enzymes 7881ad8ce9c83424f7874e70266ed2d8     
n. 酶,酵素
参考例句:
  • It was said that washing powders containing enzymes remove stains more efficiently. 据说加酶洗衣粉除污更有效。
  • Among the enzymes which are particularly effective are pepsin, papain. 在酶当中特别有效的是胃朊酶、木瓜酶。
13 inactivated 9301af139e2f8eb6dae70f855b1f1216     
v.使不活泼,阻止活动( inactivate的过去式和过去分词 )
参考例句:
  • Molluscicides are quickly inactivated by sunlight and adsorption to mud organic matter. 灭螺剂因阳光作用、泥土及有机物质的吸收会很快失效。 来自辞典例句
  • Viruses were inactivated by BPL and the toxicity measured again. BPL对病毒进行灭活,测定残存毒力。 来自互联网
14 ongoing 6RvzT     
adj.进行中的,前进的
参考例句:
  • The problem is ongoing.这个问题尚未解决。
  • The issues raised in the report relate directly to Age Concern's ongoing work in this area.报告中提出的问题与“关心老人”组织在这方面正在做的工作有直接的关系。
15 conclusive TYjyw     
adj.最后的,结论的;确凿的,消除怀疑的
参考例句:
  • They produced some fairly conclusive evidence.他们提供了一些相当确凿的证据。
  • Franklin did not believe that the French tests were conclusive.富兰克林不相信这个法国人的实验是结论性的。
16 modifications aab0760046b3cea52940f1668245e65d     
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》
TAG标签: bacteria cell synthetic
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