j*****9
发帖数: 716 | 1 http://scienceblogs.com/webeasties/2010/12/guest_post_arsenate-based_dna.php
In the wake of the NASA excitement over the new arsenic study, and my
promise to give a detailed review of the paper itself, I have recruited a
colleague with strong opinons about the work, a solid chemistry and
microbiology background, and "Dr." in front of his name to share his
analysis. I will be posting have posted my personal and less-technical take
on the whole thing soon, so stay tuned as well.
Dr. Alex Bradley u... 阅读全帖 |
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z****u
发帖数: 1007 | 2 原文
http://www.ncbi.nlm.nih.gov/pubmed/22773140
美国国家地理网站报道，2010年，美国宇航局天体生物学家在加利福尼亚州莫诺湖富含
砷的沉积物中发现了一种最怪异的生物体，这种被命名为“GFAJ-1”的细菌可以在富砷
少磷的实验室环境中茁壮生存。研究人员在《科学》杂志上发表论文称，这种细菌已经
将砷元素取代磷元素的位置，改写了自己的DNA。然而，近期两项最新研究成果表明，
这一争议性的发现事实上并非如此。
在2010年，“GFAJ-1”细菌的发现曾经引起了人们广泛关注，因为这种怪异的生物
体被认为是已经改写了自己的DNA，其中的神秘元素就是砷。当时，由美国宇航局天体
生物学家费利萨-沃尔夫-西蒙领导的研究团队因此得出结论，“GFAJ-1”细菌肯定已经
将砷写入了自己的DNA物质中，而且取代了磷元素的位置。众所周知，磷是其他所有已
知生物体DNA中的必要元素之一。两年前的发现曾经令天体生物学家们兴奋不已。磷和
砷在化学特性上有相似之处，因此，天体生物学家此前曾经推测，如果这种交换可能的
话，那么在宇宙某个意想不到的地方应该存在系外生命。
然而，在... 阅读全帖 |
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s******m
发帖数: 1154 | 3 NASA揭开谜底：地球生命形式将重新定义
美国宇航局今天表示，在地球上发现全新的微生物，它能利用砷进行新陈代谢，砷含有
剧毒。
科学家们表示，他们已经培训出一种细菌，该细菌能依靠砷维持生长，代替磷，一直以
来磷被认为是生命必须的六种元素之一。该发现推导出新的可能，即有机体可以在宇宙
中任何地方存在，甚至是在地球上利用生物化学能生长，这是过去未曾发现的。
细菌从加利弗尼亚单色湖（Mono Lake）中提取，然后密封培养。
科学家说结果如果被确认，那么“生命是什么、生命存在于何处”概念的范围将扩大。
哈佛史密森天体物理中心天文学家Dimitar Sasselov（未参与该项目）说：“当你看生
命时，它基本上是很神秘的。自然只用有限的分子和化学反应，就创造出成千上万的形
式。这第一次给了我们希望：也许还有其它选择。”
NASA天体物理学家费丽莎・乌尔夫・西蒙（Felisa Wolfe-Simon），她领
导该项目，她说：“生命如何以其它方式生存？该细菌解决了此问题。”她还说，这与
单色湖或者砷无关，而是“推开了一张门，发现我们原来认为的关于生命的固有观念并
不是那... 阅读全帖 |
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L**********O
发帖数: 1761 | 4 http://www.slate.com/id/2276919
Scientists see fatal flaws in the NASA study of arsenic-based life.
By Carl ZimmerPosted Tuesday, Dec. 7, 2010, at 10:53 AM ET
On Thursday, Dec. 2, Rosie Redfield sat down to read a new paper called, "A
Bacterium That Can Grow by Using Arsenic Instead of Phosphorus." Despite its
innocuous title, the paper had great ambitions. Every living thing that
scientists have ever studied uses phosphorus to build the backbone of its
DNA. In the new paper, NASA-funded scienti... 阅读全帖 |
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n******7
发帖数: 12463 | 5 Resisting Arsenic
The discovery of a bacterium living in the extreme conditions of Mono Lake,
California, created a major controversy because it was claimed to be able to
grow solely on arsenic and could substitute arsenate for phosphate in its
key macromolecules, including DNA. Working with the same Halomonas spp.
bacterium, known as GFAJ-1, and ultrapure reagents, Erb et al. (p. 467,
published online 8 July) found that the bacterium needed a low level of
phosphate (1.6 μM) to grow at all. Rath... 阅读全帖 |
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p*****s
发帖数: 1780 | 6 http://www.nasa.gov/home/hqnews/2010/dec/HQ_10-320_Toxic_Life.html
Dwayne Brown
Headquarters, Washington
202-358-1726
d************[email protected]
Cathy Weselby
Ames Research Center, Moffett Field, Calif.
650-604-2791
c***********[email protected]
Dec. 02, 2010
RELEASE : 10-320
NASA-Funded Research Discovers Life Built With Toxic Chemical
WASHINGTON -- NASA-funded astrobiology research has changed the fundamental
knowledge about what comprises all known life on Earth.
Researchers conducting tests in the ha... 阅读全帖 |
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T**********t
发帖数: 1604 | 7 http://www.huffingtonpost.com/2010/12/02/nasa-could-announce-arsenic-eating-bacteria_n_790954.html
WASHINGTON — The discovery of a strange bacteria that can use arsenic as
one of its nutrients widens the scope for finding new forms of life on Earth
and possibly beyond.
While researchers discovered the unusual bacteria here on Earth, they say it
shows that life has possibilities beyond the major elements that have been
considered essential.
"This organism has dual capability. It can grow with eit... 阅读全帖 |
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m******5
发帖数: 1383 | 8 A Bacterium That Can Grow by Using Arsenic Instead of Phosphorus
1. Felisa Wolfe-Simon1,2,*,
2. Jodi Switzer Blum2,
3. Thomas R. Kulp2,
4. Gwyneth W. Gordon3,
5. Shelley E. Hoeft2,
6. Jennifer Pett-Ridge4,
7. John F. Stolz5,
8. Samuel M. Webb6,
9. Peter K. Weber4,
10. Paul C. W. Davies1,7,
11. Ariel D. Anbar1,3,8 and
12. Ronald S. Oremland2
+ Author Affiliations
1.
1NASA Astrobiology Institute, USA.
2.
2U.S. Geological Survey, Menlo Park, CA, US... 阅读全帖 |
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