Bacteria created with first wholly synthetic genome.

27 May 2010

Late last week it was announced by the J. Craig Venter Institute that they had created the first synthetic cell, a variant of the bacterium mycoplasma mycoides, which is the micro-organism that causes bovine contagious pleuropneumonia. The project cost somewhere in the neighborhood of $40mus, and involved a team of geneticists sitting down and writing an entire genome of 1.1 million base pairs, using the much smaller genome of related species m.genitalium as a template. Once the smaller genome was understood it then became possible to develop a brand-new one from scratch. The research team then figured out how to apply synthetic methyl groups to the new DNA sequence so that the cellular mechanisms would accept the DNA rather than refuse to express the encoded genes. Blue Heron Bio in Washington state was then subcontracted to mass produce the new DNA sequence. Once a sufficient volume of DNA had been synthesized the JCV Institute's research team set about replacing the DNA of a culture of m.mycoides with the new DNA, which then began to express itself normally. The culture of new bacteria has begun to grow normally, in accord with the usual mathematical models of bacterial population in vitro. The new germ line has been officially dubbed Mycoplasma mycoides JCVI-syn1.0, the new suffix ostensibly representing "J. Craig Venter Institute, synthetic lifeform version 1.0."

Interestingly, the synthetic DNA sequence has a couple of messages hidden in the code to prove that the genome is, in fact, wholly artificial. Four messages can be found in the DNA: the method by which the text is encoded, a URL for people who figure out the code to go to, the names of 46 people who worked on this project, and a couple of historical quotations. Historically, the Institute has used codon encoding for watermarking and commenting, where codons are triplets of base pairs which code for amino acids, or the basic components of proteins. This time around they used a different system which encodes not only the alphabet but punctuation marks. Somehow I don't think they made it easy to find the easter eggs, though I am going to give it a shot this weekend. I find it interesting that the genome they wrote makes it much more difficult for the organism to exist outside of the lab, namely, the pathogenic properties of the original organism are thought to have been removed, a dependence on a particular antibiotic has been added, and the organism is designed to require a specific growth medium to make it unable to survive outside of culture.