Comments on: Last year: Arsenic life. This year: Chlorine life?

By: #ArsenicLife Compendium « biologicalhominin

#ArsenicLife Compendium « biologicalhominin — Fri, 18 Nov 2011 23:12:50 +0000

[...] Carl Zimmer. July 6 2011. Last year: arsenic life. This year: chlorine life? The Loom (Discover). http://blogs.discovermagazine.com/loom/2011/07/06/last-year-arsenic-life-this-year-chlorine-life/ [...]

By: Bob C.

Bob C. — Fri, 15 Jul 2011 01:53:06 +0000

Chlorinated gene pool, cool! If they try hard enough they can turn the thymine into hexachlorobenzene. But we may already have that going on in old chemical dumps.

By: Dale Hoyt

Dale Hoyt — Sun, 10 Jul 2011 20:22:29 +0000

As Mike McK & Paul Orwin point out 5-Br-uracil was known to be incorporated into DNA early on. In fact, the early study of the molecular basis of mutagenesis used it to generate mutations at a time before the genetic code was known, in the late 1950s. It was shown to be incorporated into bacteriophage DNA by Dunn & Smith in 1954 (Nature, 174:304). Another halogenated base, 5-Fl-uracil, was used by Benzer & Champe to demonstrate the existence of nonsense mutations in 1962 (PNAS, 48:1114).

By: Pat

Pat — Sun, 10 Jul 2011 14:04:14 +0000

GCACl (pronounced gee-cackle).

I know nor- is not correct but chlorinorinated sounds better than chlordesmethylated life.

5-substituted.

E. chlori.

Betting they don’t use “nuchlor mutant”.

By: Matt

Matt — Sat, 09 Jul 2011 18:49:57 +0000

clorDNAted

By: Darwin

Darwin — Sat, 09 Jul 2011 01:54:06 +0000

Sound like some intelligent designers to me!

By: Enezio E. de Almeida Filho

Enezio E. de Almeida Filho — Fri, 08 Jul 2011 09:55:04 +0000

Mutatis mutandis based life.

By: Articles. « Loftier Musings

Articles. « Loftier Musings — Fri, 08 Jul 2011 01:05:38 +0000

[...] Last year: Arsenic life. This year: Chlorine life? [...]

By: Darwiniana » Chlorine life?

Darwiniana » Chlorine life? — Thu, 07 Jul 2011 16:46:49 +0000

[...] Last year: Arsenic life. This year: Chlorine life? [...]

By: Laura

Laura — Thu, 07 Jul 2011 16:14:10 +0000

“One minor quibble, however; you write “This E. coli is different from ordinary E. coli, with over a thousand mutations that enable it to take up chlorouracil” when it is very unlikely that all of the noted mutations are actually involved in that change. I would guess that many are what might be termed “collateral damage,” and it will take further study to identify the key mutations.”

Actually when I spoke to the researchers last week that’s exactly what they said. They’re now going back and trying to work out which mutations confer this ability and are necessary. They’re also trying to make the bug so it can’t survive on T, which at the moment it can if no chlorouracil available

By: Mike McK

Mike McK — Thu, 07 Jul 2011 15:47:06 +0000

Back in the 70′s and probably earlier Bromo deoxy uracil was used to mark newly synthesized DNA from bulk DNA by taking advantage of the fact that the BUdR was denser than deoxy thymidine. As a result, in an ultracentrifuge at equilibrium, the BUdR DNA banded at a lower portion of the tube than normal DNA.

It was not possible to do this over the long term, but the bugs had the enzymes to incorporate the BromoT as well as normal.

By: Scienceblogging Networks Come of Age, But What About Health? | Common Sense

Scienceblogging Networks Come of Age, But What About Health? | Common Sense — Thu, 07 Jul 2011 15:00:34 +0000

[...] exactly create a lot of overlap. While someone who is curious enough to read Carl Zimmer on arsenic life is probably a tempted by an Ed Yong post on dinosaurs, a reader looking for sunscreen advice [...]

By: Khyati

Khyati — Thu, 07 Jul 2011 13:18:47 +0000

That’s some of real good works!! Paul’s post enlightens its connection with base alterations. And it might give a new hope to know future predictions of evolution of living organism, and that too starting with the earth’s first creature ‘bacteria’. Its important to know here that due to this alterations the organic compound becomes more lipophilic and any changes brought about in their membrane properties.

Better to call it ‘chlorine-life’ knowing its future prospects.

By: Joe

Joe — Thu, 07 Jul 2011 08:27:32 +0000

I gots chlorine in my pool

By: Ariel Goldstein

Ariel Goldstein — Thu, 07 Jul 2011 06:10:51 +0000

Chlorine augmented life, or chlorophilic lifeforms @ArielOnHealth

By: Paul Orwin

Paul Orwin — Thu, 07 Jul 2011 03:03:17 +0000

I’m surprised you didn’t mention that 5-bromouracil uptake has been used for years as a way to label metabolically active cells (because it is incorporated into the DNA and can be detected using an antibody). This has been used by environmental microbiologists to identify the metabolically active group in a mixed sample for metagenomics.

Immunochemical Detection and Isolation of DNA from Metabolically Active Bacteria
Ena Urbach,* Kevin L. Vergin, and Stephen J. Giovannoni
Applied and Environmental Microbiology, March 1999, p. 1207-1213, Vol. 65, No. 3

The differences here are 1) a different halogen, obviously, and 2) much higher concentrations. So the biochem strategy is pretty clear cut (grow them on slowly increasing concentrations, select for fast growth with lots of chlorine). It will be interesting to see what mutations are shown to be important in this adaptation, for various reasons, but as your other microbiology inclined correspondents said, this doesn’t seem nearly as contentious of a report.

By: Matt R

Matt R — Thu, 07 Jul 2011 01:23:39 +0000

Would it be better to call it chlorine-coded life rather than chlorine-based life?

By: Mr Z

Mr Z — Wed, 06 Jul 2011 23:01:49 +0000

Seems tome a sub-note on the word life would be enough
Life(c) – carbon
Life(cl) – chlorine
Life(as) – arsenic

By: Charlie Petit

Charlie Petit — Wed, 06 Jul 2011 21:53:27 +0000

Obvious. We have the word already for our swimming pools and hot tubs. This life form is chlorinated. Still carbon-based. But it’s spa-ready.

By: Guy Plunkett III

Guy Plunkett III — Wed, 06 Jul 2011 21:16:38 +0000

Very interesting … One minor quibble, however; you write “This E. coli is different from ordinary E. coli, with over a thousand mutations that enable it to take up chlorouracil” when it is very unlikely that all of the noted mutations are actually involved in that change. I would guess that many are what might be termed “collateral damage,” and it will take further study to identify the key mutations. As for a better shorthand descriptor, perhaps some play on “When life gives you …”?

By: Redshift

Redshift — Wed, 06 Jul 2011 20:35:53 +0000

I don’t understand why it is being called chlorine-based (nor why the previous story was called arsenic-based). They’re still quite clearly carbon-based lifeforms. Carbon is the core component, forming a backbone of structure and reactability- the base. These chlorouracil-uptake coli are neat, and I wish the researchers the best, but you can’t call it chlorine-based life. Chlorine-uptake life? chlorouracil-uptake? The other lot could be called arsenic-dependent, although the new ones discussed here are not -yet- dependent on chlorouracil