I am the family face; flesh perishes. I live on, projecting trait and trace through time to times anon, and leaping from place to place over oblivion.
So wrote Thomas Hardy in his poem, Heredity, describing direct descent of life from one generation to the next. Indeed, the poem reflects the DNA in our genome. Dr.Drew Endy of MIT quoted this when he described how people at the J. Craig Venter Institute (JCVI) bypass nature’s constraint of direct descent. Scientists there have used chemistry and biochemistry to produce the first synthetic genome in the laboratory. They chemically synthesized many fragments of the DNA, encoding the 582,970-units-long genome of a bacterium called Mycoplasma genitalium. Next, they assembled these fragments in perfect order to generate the genome of the bacterium.
The DNA sequence of the synthetic one was confirmed to be identical to the natural one. While the DNA pieces were synthesized chemically, the stitching together was done using the biochemical machinery of a host cell. About 100 pieces of the genome, each 5000-7000 units long in DNA sequence, were first joined to produce 25 sub-assemblies, each about 24000 base pairs long. These were then introduced into the bacterium E. coli to produce sufficient DNA for the next steps. Next, they repeated the procedure to generate large fragments comprising l/4th of the whole genome of M.genitalium.
Now, they used the clever trick of exploiting the process called homologous recombination. This is a basic essential process in every cell, which physically rearranges the two strands of DN The JCVI researchers inserted the synthesized DNA fragments into yeast and utilized its homologous recombination ability to generate the whole 580,000 long genome of M.genitalium in one step.
This is clearly a landmark work that leads into the brave new world of synthesizing life itself in the laboratory. It was hardly 200 years ago when Friedrich Wohler synthesized urea, an organic molecule, in the chemical laboratory, thus throwing out the notion of ‘vital forces’ involved in the components of living organisms. What is the next step, making life itself in the lab, bypassing nature? With single cell organisms like M.genitalium, it might not be far away. It is now possible in the lab to do so, by inserting the genome into a ‘host’ cell and asking the latter to make the bacterium of your choice. If only we find a way to insert the bacterial genome into this proto-cell, and somehow trigger it to make the bacterium itself! We would have chemically created life in the la This is not a pipedream; JCVI scientists are already on the job, and my bet is they will do it within a few years.
This surely raises ethical questions, a matter that JCVI is keenly aware of and is already engaged in with ethicists. Even their present work on M.genitalium was done with prior approval of ethical experts. But then, today it is M.genitalium, tomorrow it could be a more advanced, multi-cellular organism, and that could flummox even the ethicist. Assisted reproduction, which is the other side of the coin and truly a recently initiated technology, has become ethically and morally acceptable. Cloning of Dolly, the sheep, has not raised any outrage, but cloning a human certainly does.