Hacking DNA: Scientists Generate New Organisms Not Found in Nature
An international team of researchers has now succeeded in generating a bacterium possessing a DNA in which thymine is replaced by the synthetic building block 5-chlorouracil (c), a substance toxic for other organisms. The genetic information of all living cells is stored in the DNA composed of the four canonical bases adenine (A), cytosine (C), guanine (G) and thymine (T).
The experimental work was based on a unique technology that enables the directed evolution of organisms under strictly controlled conditions. Large populations of microbial cells are cultured for prolonged periods in the presence of a toxic chemical -- in this case, 5-chlorouracil -- at sublethal levels, thereby selecting for genetic variants capable of tolerating higher concentrations of the toxic substance.
In response to the appearance of such variants in the cell population the concentration of the toxic chemical in the growth medium is increased, thus keeping the selection pressure constant. This automated procedure of long term evolution was applied to adapt genetically engineered Escherichia coli bacteria unable to synthesize the natural nucleobase thymine to grow on increasing concentrations of 5-chlorouracil.
After a culture period of about 1000 generations descendants of the original strain were obtained which used 5-chlorouracil as complete substitute for thymine. Subsequent genome analysis revealed numerous mutations in the DNA of the adapted bacteria. The contribution of these mutations to the adaptation of the cells towards the halogenated base will be the subject of follow-up studies.
Besides the obvious interest of this radical change in the chemistry of living systems for basic research the scientists consider the outcome of their work also to be of importance for "xenobiology," a branch of synthetic biology. This young area of the life sciences aims at the generation of new organisms not found in nature harboring metabolic traits optimized for alternative modes of energy production or for the synthesis of high value chemicals.
Like GMOs, such organisms are seen as a potential threat for natural ecosystems when released from their laboratory confinements, either through direct competition with wild type organisms or through diffusion of their "synthetic" DNA.
Scientists have recognized that physical containment cannot in every single case prevent engineered live forms from reaching natural habitats, in the same way as radioactive isotopes can leak into the surroundings of a nuclear power plant.
However, synthetic organisms like those evolved by Rupert Mutzel (Institut für Biologie, Freie Universität Berlin) and Philippe Marlière (Heurisko USA Inc.) and their collaborators which depend on the availability of substances for their proliferation not found in nature or which incorporate non-natural building blocks in their genetic material could neither compete nor exchange genetic messages with wild type organisms, but would die in the absence of the xenobiotic.
The Daily Galaxy via Freie Universitaet Berlin via AlphaGalileo
In response to the appearance of such variants in the cell population the concentration of the toxic chemical in the growth medium is increased, thus keeping the selection pressure constant. This automated procedure of long term evolution was applied to adapt genetically engineered Escherichia coli bacteria unable to synthesize the natural nucleobase thymine to grow on increasing concentrations of 5-chlorouracil.
After a culture period of about 1000 generations descendants of the original strain were obtained which used 5-chlorouracil as complete substitute for thymine. Subsequent genome analysis revealed numerous mutations in the DNA of the adapted bacteria. The contribution of these mutations to the adaptation of the cells towards the halogenated base will be the subject of follow-up studies.
Besides the obvious interest of this radical change in the chemistry of living systems for basic research the scientists consider the outcome of their work also to be of importance for "xenobiology," a branch of synthetic biology. This young area of the life sciences aims at the generation of new organisms not found in nature harboring metabolic traits optimized for alternative modes of energy production or for the synthesis of high value chemicals.
Like GMOs, such organisms are seen as a potential threat for natural ecosystems when released from their laboratory confinements, either through direct competition with wild type organisms or through diffusion of their "synthetic" DNA.
Scientists have recognized that physical containment cannot in every single case prevent engineered live forms from reaching natural habitats, in the same way as radioactive isotopes can leak into the surroundings of a nuclear power plant.
However, synthetic organisms like those evolved by Rupert Mutzel (Institut für Biologie, Freie Universität Berlin) and Philippe Marlière (Heurisko USA Inc.) and their collaborators which depend on the availability of substances for their proliferation not found in nature or which incorporate non-natural building blocks in their genetic material could neither compete nor exchange genetic messages with wild type organisms, but would die in the absence of the xenobiotic.
The Daily Galaxy via Freie Universitaet Berlin via AlphaGalileo
Comments
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"Scientists Generate New Organisms Not Found In Nature"
WHAT COULD GO WRONG
Posted by: Matt | June 30, 2011 at 07:37 AM
Well lets hope this organism never gets out by accident and infects life as we know it. Could be the doomsday bug for everything alive.
Posted by: Paul | June 30, 2011 at 07:42 AM
I'm unclear how xenobiology, the speculative study of extraterrestrial life, is a branch of synthetic biology.
Posted by: KT | June 30, 2011 at 08:14 AM
Like children playing with fire!
Posted by: sensate | June 30, 2011 at 06:41 PM
I'm sure we're finally approaching some kind of end of times (for humanity), all these technologies will surely fall into the wrong hands sooner or later (in a few decades, maybe a century or two). Different groups of people hate each other too much, and will fight to the death to defend their beliefs, however wacky. It's sad because it could have been beautiful.
Posted by: UltraBen | June 30, 2011 at 07:34 PM
Unless it too, mutated! And changed into something that eludes detection.
Posted by: `dr burke | June 30, 2011 at 09:06 PM
I agree this is deliberately looking for trouble. Any of these mad scientists ever see a science fiction movie? Mary Shelley anyone?
Posted by: Ray in Vegas | June 30, 2011 at 09:19 PM
Ah - the master of desaster is on work! Thank you! We have not enough problems here on earth and not enough possibilities to terminate mankind!
Posted by: starsailor | July 01, 2011 at 07:05 AM
Ah - the master of desaster is on work! Thank you! We have not enough problems here on earth and not enough possibilities to terminate mankind!
Posted by: starsailor | July 01, 2011 at 07:05 AM
Evolution has been created in laboratory.
That's weird.
ACCG-DNA organism (rather than ATCG-DNA) could exist on exoplanets.
That's cool.
Extraterrestrial organisms artifically created on Earth could overcome terrestrial organisms.
That's scary.
Posted by: jumpjack | July 01, 2011 at 07:29 AM
Apparently not one of the above posters noticed that this technology generates bacteria that are dependent on substances not commonly found in nature. In other words, if let out into the wild these things would die before they could do enough damage to even be noticed.
Posted by: Bob Greenwade | July 01, 2011 at 07:32 AM
Is it unreasonable of me to wish we were first on a few other planets before we venture down such paths? I mean, our scientists are constantly discovering their previous arrogance was absurd, yet they keep on behaving in the same manner, applying the same absurd arrogance moving forward. For such smart people they sure can be so dumb. And when that genius/imbecile hybridization is setting foot in grounds such as these...well, I guess keeping my fingers crossed is about as productive a countermeasure as I could perform. Maybe I could build my own intergalactic spacecraft and just get the heck outta here regardless...not base solely, or even primarily on this feat I assure you.
Posted by: SiliconJon | July 01, 2011 at 08:08 AM
An international team of researchers has now succeeded in generating a bacterium possessing a DNA in which thymine is replaced by the synthetic building block 5-Chlorouracil (c), a substance toxic for other organisms.
Posted by: WFG | July 04, 2011 at 01:23 AM
@The above fearmongers: If you finished reading the article, you would have understood that the whole point of this experiment is to create creatures that would harmless were they to escape containment. This procedure is working to make genetic experimentation safer for the rest of the world. Considering all the things we can learn in this field of study, this should be welcome news to everyone.
Posted by: Voiceofreason | July 04, 2011 at 03:52 AM
This makes a lot of sense dude .Wow
www.Privacy-Toolz.tk
Posted by: WuxRoo | July 04, 2011 at 09:55 AM
Wow, some of you people seem to be able to comment but yet not read!
If you actually read the article, you will see that the reason they are developing these organisms is so that if they genetically engineer certain bacteria for a specific purpose, these bacteria will rely on synthetically produced food that does not exist in the natural world, and thus they cannot break loose and wreak havoc on the environment.
Posted by: The Mikeness | July 04, 2011 at 12:49 PM
What everyone fails to pick up on is not the bacteria, but the technology.
The closest poster presents this:
----
Different groups of people hate each other too much, and will fight to the death to defend their beliefs.
----
How easy would it be for some rogue group to use the same method to expose tuberculosis to all of our antibiotics in very small concentrations for a thousand generations increasing overtime untill the bacterium is completely resistant and has genetic modifications that would allow it to easily and quickly adapt to any new antibiotic. Then take said bacterium, grow it, put it in a suitcase, and leave it in some public place?
While this is interesting, the technology is frightening in its application.
Posted by: But what if... | July 04, 2011 at 01:32 PM
Stop ****ing around and make me a bigger wang
Posted by: Mike | July 04, 2011 at 02:20 PM
Stop ****ing around and make me a bigger wang
Posted by: Mike | July 04, 2011 at 02:20 PM
title is wrong and misleading. what scientists do is to modify dna of small organisms. you can't say that its a whole new organism.. just a modification.
Posted by: Mark | July 04, 2011 at 02:29 PM
Voiceofreason, please don't encourage redefining critical thought as fearmongering.
Posted by: SiliconJon | July 04, 2011 at 02:52 PM
tl;dr After growing in sublethal toxin concentrations for 1000 generations, bacteria evolve to become dependent on toxin to survive.
Posted by: Eric | July 04, 2011 at 10:09 PM
tl;dr After growing in sublethal toxin concentrations for 1000 generations, bacteria evolve to become dependent on toxin to survive.
Posted by: Eric | July 04, 2011 at 10:21 PM
Oh snap! This is going to get loose, and cause a zombie outbreak!
Posted by: Zombie | July 07, 2011 at 11:02 PM
Oh snap! This is going to get loose, and cause a zombie outbreak!
Posted by: Zombie | July 07, 2011 at 11:02 PM