Editorial: Producing a synthetic bacterium
Published in the Hindu on August 22, 2007
Whether the claim made by Craig Venter, the famous and controversial scientist, and his team working at the Maryland based J. Craig Venter Institute in a patent filed last year to produce a truly ‘synthetic’ bacterium with minimal genomes is significant is a debatable point. While the genome of the bacterium was produced synthetically in the laboratory, a ‘synthetic’ bacterium, which has been named as Mycoplasma laboratorium in the patent and will eventually be created using the minimal genome, cannot in the strict sense be called man-made. To be called synthetic, no naturally available component should be used. In that sense, the scientists from the reputed institute, known for being the pioneers in sequencing the genome of a living organism and the first to publish the sequence of the human genome, will at best be able to produce a semi-synthetic M. genitalium bacterium. The synthetic genome produced by them will be put into a naturally occurring cell which will have only its nucleus removed. While removing the nucleus of the cell ensures that its genetic material is removed, the cell will still contain many other materials without which the M. genitalium genome introduced cannot survive and reproduce. The procedure described by them is, in many ways, similar to that followed for producing embryonic stem cells. Many scientists are working to produce a truly synthetic organism that has no trace of natural components. Synthetic flu virus and polio virus were built from scratch using the genome sequence a few years ago. Yet they were not considered synthetic as viruses need a host to replicate.
Apart from producing the synthetic genome, their achievement has been to arrive at the minimum number of essential genes needed for sustaining life. The wall-less M. genitalium bacterium with just 482 genes, the smallest number seen in any naturally occurring organism, is the best experimental platform and hence the natural choice for scientists to produce a bacterium with ‘minimal genome.’ Despite the small size of the genome, the bacterium still has many non-essential genes and scientists have been working for years to identify such genes. The patent filed by them cites 381 as the minimal genome for the M. laboratorium that would allow the bacterium to replicate in a controlled environment. This is one less than the number they had stated in a paper published in a journal last year. While their work on the minimal genome and synthetic genome is indeed a great feat, as it lends itself to a variety of applications, filing the patent application has irked many. While patents have been granted to individual genes, this is the first time a patent has been filed for an entire genome sequence. If granted, it will handicap researchers in the area and may not augur well for the advancement of science.
