Synthetic life?

Did Craig Venter create life?

There has been a huge amount of media attention and a torrent of breathless commentary concerning Craig Venter’s recent publication, “Creation of a Bacterial Cell Controlled by a Chemically Synthesized Genome”.

Much of the fuss stems from the assertion that the Venter group has created synthetic life – created a new living organism from inert materials.  Is this really true?

What actually happened here was a complete reprogramming of an existing organism via the introduction of a “synthetic” genome.  Please note that “synthetic” refers to the code’s method of manufacture (via a DNA synthesizer) and not that the code itself was generated de novo. The sequence was edited from the known genome of an existing species (M. mycoides).

Furthermore, achieving the end result of a “new” organism was not possible without substantial help from other living systems. Specifically, the conjugation of the synthesized DNA strands into a genome-length construct required input from physiologic processes in yeast cells and E. coli. Plus, the newly formed genome had to be inserted into a living organism (M. capricolum) to allow the “new creation” to develop (M. mycoides JCVI-syn1.0).  The host cell cytoplasm and the epigenetic machinery which supported replication of the synthetic genome was, obviously, not of synthetic origin.

Hence, this “synthetic” lifeform required a lot of help from a variety of living cells to get off the ground.

When asked about his breakthrough at a Congressional Hearing on May 27, 2010, Venter commented “We do not consider this to be ‘creating life from scratch’; rather, we are creating new life [emphasis added] out of already existing life using synthetic DNA to reprogram the cells to form new cells with functions that are specified by the synthetic DNA.”

Once again the yeast, E.coli and M. capricolum were definitely not synthetic. Also “creating new life?”  Probably more accurate (but less attention grabbing) to say “we transformed an existing cell with a genome built from components based on another related organism that we manufactured with a DNA synthesizer and assembled in yeast and E. coli .”

The great technical achievement here is that it was possible to modify a self-replicating living organism with a different genome built from machine-derived DNA and have the new organism replicate successfully based on the new DNA.  In terms of applications, this work could allow alterations to simple organisms, such as the influenza virus, in order to quickly make improved vaccines as epidemics appear.

But artificial life?  Not at all.  As Venter and colleagues have demonstrated, life still comes from life.