First Successful Genome Transplant In Bacteria

eldavojohn writes "Researchers reported the first genome transplant from one bacterium to another, thereby transforming the species from M. mycoides to M. capricolum. The research, published in Science, shows that it is possible to achieve a success rate of 1 in 150,000 genome transplants in bacteria. While this may not seem like very good odds, it's actually a major step towards synthetic life, opening up the possibility of tailoring bacteria to our needs. The article mentions medical uses and fuel production as possible applications."

Comments

Re:Strong containment

[Valar]

Well, except that wide spectrum antibiotics target whole categories of bacteria. What really matters is the type of cell wall, because that is usually what antibiotics disrupt. As long as the resulting bacteria has a cell wall like the ones in other bacteria (and I see no reason why they wouldn't be designed that way), then we will have no problems, especially if it is a gram positive bacteria.

Re:Strong containment

[Andy Dodd]

The bugs have been successfully designing themselves that way thanks to our good friend evolution.

If someone wants to create an antibiotic-resistant superbug, it would be much easier for them to start with existing antibiotic-resistant bugs and tweak them with existing well-established techniques.

The big news of this article is not that genetic material was transplanted, but that the *full and complete* genome was transplanted. To be honest, while it's an impressive feat, for 99% of the applications mentioned in the article summary, existing "partial genome" transplantation techniques are more than sufficient. People have been doing partial genome transplants with success for nearly three decades now - see http://en.wikipedia.org/wiki/Insulin#Timeline_of_i nsulin_research .

Article is useless

[the_kanzure]

Most informative part:

The researchers explained that the transplantation method is simple in concept, though complicated to execute. First, the proteins were stripped from the M. mycoides LC cells, resulting in naked DNA that can be passed between cells. Then this intact DNA was incubated briefly with M. capricolum cells, soaking in a solution that caused the M. capricolum cells to fuse together. As two of these recipient cells fused, they sometimes encapsulated a donor DNA chromosome.

And then the citation:

Lartigue, Carole, Glass, John I., Alperovich, Nina, Pieper, Rembert, Parmar, Prashanth P., Hutchison III, Clyde A., Smith, Hamilton O., and Venter, J. Craig. Genome Transplantation in Bacteria: Changing One Species to Another. 3 August 2007, Vo. 317, Science.

Abstract:

Originally published in Science Express on 28 June 2007
Science 3 August 2007:
Vol. 317. no. 5838, pp. 632 - 638
DOI: 10.1126/science.1144622

Genome Transplantation in Bacteria: Changing One Species to Another
Carole Lartigue, John I. Glass,* Nina Alperovich, Rembert Pieper, Prashanth P. Parmar, Clyde A. Hutchison, III, Hamilton O. Smith, J. Craig Venter

As a step toward propagation of synthetic genomes, we completely replaced the genome of a bacterial cell with one from another species by transplanting a whole genome as naked DNA. Intact genomic DNA from Mycoplasma mycoides large colony (LC), virtually free of protein, was transplanted into Mycoplasma capricolum cells by polyethylene glycol-mediated transformation. Cells selected for tetracycline resistance, carried by the M. mycoides LC chromosome, contain the complete donor genome and are free of detectable recipient genomic sequences. These cells that result from genome transplantation are phenotypically identical to the M. mycoides LC donor strain as judged by several criteria.

The J. Craig Venter Institute, Rockville, MD 20850, USA.

* To whom correspondence should be addressed. E-mail: jglass@jcvi.org

But would it be too painful to actually add in relevant information from the published article? Not all of us know where to go get "Science", nor do we have magical access. Slashdot editors, if you would be so kind- stop accepting articles about papers behind paywalls. Some of us want to actually discuss the contents of these articles, the research methods, to look into what's actually going on ... not this hype that tells us nothing and wastes our time. ("You must be new!")

Anyway, genome transplantation means that maybe we can get the genome of our stem cells transplanted into bacteria. Just store lots of stem cell DNA, and then one day start the procedure to make the bacteria uptake the DNA and--- well, the current problem with this is that the human genome is much different from bacterial genomes, and so there will undoubtedly be way too many problems with the host bacteria, i.e. trying to make some of the proteins and biomolecules that actually causes self-destruction, but the concept/hope is still there.

BTW, the group that this article is about has been taking up way too much of our collective attention:
* Team claims synthetic life feat
* Venter Institute claims patent on synthetic life
* and now this.
And I should probably link over to this site.

Re:Article is useless

[Anonymous Coward]

Genome Transplantation in Bacteria: Changing One Species to Another
Carole Lartigue, John I. Glass,* Nina Alperovich, Rembert Pieper, Prashanth P. Parmar, Clyde A. Hutchison, III, Hamilton O. Smith, J. Craig Venter

As a step toward propagation of synthetic genomes, we completely replaced the genome of a bacterial cell with one from another species by transplanting a whole genome as naked DNA. Intact genomic DNA from Mycoplasma mycoides large colony (LC), virtually free of protein, was transplanted into Mycoplasma capricolum cells by polyethylene glycol-mediated transformation. Cells selected for tetracycline resistance, carried by the M. mycoides LC chromosome, contain the complete donor genome and are free of detectable recipient genomic sequences. These cells that result from genome transplantation are phenotypically identical to the M. mycoides LC donor strain as judged by several criteria.

The J. Craig Venter Institute, Rockville, MD 20850, USA.

* To whom correspondence should be addressed. E-mail: jglass@jcvi.org

It has been known ever since Oswald Avery's pioneering experiments with pneumococcal transformation more than six decades ago, that some bacteria can take up naked DNA (1). This DNA is generally degraded or recombined into the recipient chromosomes to form genetic recombinants. DNA molecules several hundred kilobase pairs (kb) in size can sometimes be taken up. In recent studies with competent Bacillus subtilis cells, Akamatsu and colleagues (2, 3) demonstrated cotransformation of genetic markers spread over more than 30% of the 4.2-megabase pair (Mb) genome using nucleoid DNA isolated from gently lysed B. subtilis protoplasts. Artificial transformation methods that employ electroporation or chemically competent cells are now widely used to clone recombinant plasmids. Generally, the recombinant plasmids are only a few kilobase pairs in size, but bacterial artificial chromosomes (BACs) greater than 300 kb have been reported (4). Recombinant plasmids coexist with host-cell chromosomes and replicate independently. Two other natural genetic transfer mechanisms are known in bacteria. These are transduction and conjugation. Transduction occurs when viral particles pick up chromosomal DNA from donor bacteria and transfer it to recipient cells by infection. Conjugation involves an intricate mechanism in which donor and recipient cells come in contact and DNA is actively passed from the donor into the recipient. Neither of these mechanisms involves a naked DNA intermediate.

In this paper, we report a process with a different outcome, which we call "genome transplantation." In this process, a whole bacterial genome from one species is transformed into another bacterial species, which results in new cells that have the genotype and phenotype of the input genome. The important distinguishing feature of transplantation is that the recipient genome is entirely replaced by the donor genome. There is no recombination between the incoming and outgoing chromosomes. The result is a clean change of one bacterial species into another.

Work that is related to the process we describe in this paper has been carried out or proposed for various species. Itaya et al. transferred almost an entire Synechocystis PCC6803 genome into the chromosome of a recipient B. subtilis cell using the natural transformation mechanism. The resulting chimeric chromosome had the phenotype of the B. subtilis recipient cell. Most of the Synechocystis genes were silent (5). A schema for inserting an entire Haemophilus influenzae genome as overlapping BACs into an Escherichia coli recipient has also been proposed; however, those authors have pointed out difficulties arising from incompatibility between the two genomes (6). Transplantation of nuclei as intact organelles into enucleated eggs is a well-established procedure in vertebrates (7-9). Our choice of the term "genome transplantation" comes from the similarity to eukaryotic nuclear transplantation in which one genome is cleanly replaced by another.

Ge

Re:A step forward, but questions remain

[rritterson]

That is, again, speculation on the part of the authors. In the paper, the authors only say they believe the cells are fusing because eukaryotic cells also fuse in the same medium, with again no evidence to support the claim. So, we don't even know for sure whether the bacteria are fusing, let alone whether the concentration they used is somehow optimal for fusion to take place.

Full Science paper.... they did it right..

[tempest69]

http://www.sciencemag.org/cgi/content/full/317/583 8/632

The authors agreed that a single PCR wasnt enough, so they went with a hindIII digestion and an agarose gel run, to make sure that the pieces were all the right size, and nopt some funky recombination. They also managed a few southern blots to further ensure their results. AND they did 1300 Random Sequences (with luck a sequence can be read to 1000ish base pairs..), and IT ALL MATCHED.... 1.09 million base pairs all fit right...

So my point is that they did the work, made sure it was bulletproof, got accepted into a major journal. And sure they dont know the whole story of whats going on, but it doesnt matter, they DID IT, a full Genome transplant, with proper methods used to ensure its validity..

Storm