In our last two blog posts–dated July 12, 2010 and July 18, 2010, we discussed the “synthetic cell” that was recently constructed by researchers at the J. Craig Venter institute. As we discussed, at least several leading bioethicists and philosophers said that the construction of a “synthetic” microbial cell refuted vitalism–i.e., the contention that there is something special about processes in living organisms that cannot be artificially created from nonliving systems–once and for all. However, leading scientists (including Nobel Prize winners and leading synthetic biologists) disagreed with that assessment. We said that we agreed with the leading scientists, and gave our reasons why.
Meanwhile, a one-page essay by bioethicist Gregory Kaebnick, Ph.D. appeared In the July 2010 issue of The Scientist (registration required). Dr. Kaebnick is the editor of the bioethics journal The Hastings Center Report, and a co-investigator of a Hastings Center research project on synthetic biology. Dr. Kaebnick agrees with the leading scientists, and with us, even though his friend and colleague Arthur Caplan is one of the bioethicists who says that the “synthetic cell” has refuted vitalism.
According to Dr. Kaebnick, what the Venter group created was not a synthetic cell, but a synthetic genome. (As we stated in our second article, the researchers had help from yeast in creating the “synthetic” genome–perhaps it is really a semi-synthetic genome.) But the Venter group says that since the genome took over the cell it was transferred into, and since the genome is synthetic, therefore the cell is synthetic. But that assumes a top-down control of a cell by its genome (i.e., genetic determinism). Dr. Kaebnick argues that one might instead say that the cell and the genome worked out their differences and collaborated, or that the cell “adopted” the genome. He goes on to assert that we may not know enough to say which of these two metaphors is most adequate.
Then Dr. Kaebnick goes on to ask whether even if the Venter group did create a synthetic cell, whether that really demystified life at all. You will have to read his article to follow that argument.
From our point of view, even if the “top down” control model is the most nearly correct, without a pre-formed cell it would have been impossible to use the synthetic genome to create a living organism. Researchers cannot, at least at present, create a cell, with its membranes, organization of biomolecules, biochemical systems, etc. that is necessary for a genome to work to express itself in a living system.
Moreover, with the discoveries on epigenetics in the last decade or so, researchers know that a “top down” control model–especially in multicellular eukaryotic organisms–does not fully account for how cells and organisms work. The environment can mediate changes in chromatin, such as DNA methylation and histone modification, which can be passed down from cell to cell and in some cases even to the next generation.
Thus the issue of “top down” genetic determinism versus collaboration between a cell and its genome has implications for cutting-edge biological research. Since some drug discovery researchers have been working on discovery and development of epigenetics-based drugs, it is of interest to the biotechnology/pharmaceutical industry as well. Several such drugs, including Celgene’s DNA methyltransferase inhibitors and histone deacetylase inhibitors that we mentioned in an earlier blog post, are already on the market.