August 27, 2009

Still not "new" or "artificial"

ResearchBlogging.orgAfter having headed the efforts to transplant a bacterial genome from one species to the other and to create a synthetic bacterial genome from scratch, Craig Venter predicts to finally have a synthetic species created before the end of the year. Judging by the results published in advance on the Science express website last week (find it on the print issue of Science soon), it seems his J. Craig Venter Institute (JCVI) is well on its way.

In a post from last year I commented on the JCVI's creation of a synthetic Mycoplasma genitalium genome and lamented the media coverage's choice of terms ("playing god", "man-made life", "creating life from scratch", et c.) to describe the in and of themselves impressive results. I wrote:

... terms like "playing god" or "creating new life from scratch" are inaccurate because technically you'd have to insert the artificial genome into a host cell and produce a viable organism, one that could replicate itself, before you'd have created life. Theoretically this isn't impossible or even particularly incredible, but it poses a whole lot of technical demands. And would this life actually really be "new" or even entirely synthetic?

With these latest results it seems we're a step closer to just that, even if it still doesn't fulfill the criteria I'd use to characterize a completely new or artificial or even synthetic organism.

By cloning a transformed version of a Mycoplasma mycoides genome in yeast cells, then transplanting it into a recipient cell of a closely relates species, Mycoplasma capricolum, and producing viable colonies of engineered M. mycoides, basically "re-booting" cells with a new genome (how cool is that!?), the team at JCVI developed a protocol through which it would be possible to take a completely synthetic genome, clone it and introduce it into "empty" receptor cells to produce a "new" and engineered species.

The difficulty had been to successfully transplant the engineered bacterial genome from the yeast cells to the final receptor bacterial cell. The use of yeast cells to engineer the genome is essential since there are well-established genetic tools for yeast that are not available for the bacteria used. To solve this issue the team destroyed the recipient cell's defense against foreign DNA, a restriction endonuclease that cleaves foreign DNA into pieces, and modified the donor genome so that it exhibited the same methylation pattern as native M. capricolum DNA. Methylation is a secondary modification of the DNA molecule that affects gene expression and is used by bacterial cells to prevent their own DNA from being cleaved by endonucleases.

It's going to be very interesting to see if JCVI will be able to combine their ability to synthesize a bacterial genome with these latest achievements to create a synthetic species before year's end. Whenever they do it, the question still remains if this would constitute "new" or "artificial" life. In my opinion it would still very much be "old life" put together in new ways, which is still a great feat and an important advance in science, don't get me wrong; but "new life" or "artificial life" are nothing by hype-y buzzwords. I've written two posts about it.

The media reports this time around have so far been better than last year, without hyperbolic mentions of "playing god" or anything like that. There's the article I link to at the top of this post from The Times Online, and another at MIT's Technology Review. Meanwhile a post at a Discover Magazine blog opens with:

Although scientists may not have come close to cataloging all the different kinds of life on the planet, genetics pioneer Craig Venter is pressing ahead with his plans to create biology version 2.0.

Biology version 2.0!? That makes no sense whatsoever.

Lartigue, C., Vashee, S., Algire, M., Chuang, R., Benders, G., Ma, L., Noskov, V., Denisova, E., Gibson, D., Assad-Garcia, N., Alperovich, N., Thomas, D., Merryman, C., Hutchison, C., Smith, H., Venter, J., & Glass, J. (2009). Creating Bacterial Strains from Genomes That Have Been Cloned and Engineered in Yeast Science DOI: 10.1126/science.1173759

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1 comment:

  1. Hi Daniel,

    Once again, you made it to my weekly "Picks of the week" of posts in molecular biology aggregated in ResearchBlogging.
    You can check the post at



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