"This is an important step, we think, both scientifically and philosophically," Dr. Venter said in an interview with the journal Science, which is publishing the research this week. "It's certainly changed my views of definitions of life and of how life works.
The work being actively publicized in multiple venues involved the complete synthesis of a bacterial genome (based on that of Mycoplasma mycoides) of slightly more than one million base pairs and its insertion into cells of a related microorganism (Mycoplasma capricolum). These host cells had previously been deprived of their natural genomes (presumably against their will). The new cells, which Venter refers to as "synthetic cells," are partly, but only partly, "synthetic." While all or most of the genome was physically constructed by man-made devices, the cytoplasm and cell membranes were the results of natural processes. In any case, the "new" cells were able to reproduce spontaneously and, according to the authors, exhibited the behavior and attributes (i.e. phenotype) expected from the exogenously-derived genomes inserted into them.
Therefore, it was most fortunate to have David Baltimore on the line with the Diane Rehm Show interviewer (Steve Roberts filling in for the eponymous host) and his other guests. Dr. Baltimore, one of the most eminent molecular biologists of the past half century, pointed out that what Dr. Venter and his associates accomplished involved impressive technical achievements but that it was not really profoundly new in a scientific sense. As Baltimore noted, molecular biologists have been operating for many years on the assumption that genes determine many aspects of cellular function. Furthermore, scientists have been routinely transfecting (i.e., inserting) foreign pieces of DNA into all sorts of cells to confer on those recipient cells the abilities to make proteins that they otherwise would not make and to thereby influence, sometimes decisively, their functional properties more broadly. Nevertheless, the JCVI investigators deserve credit for extending the range of what they refer to as "genome transplantation."
Similarly, synthesizing DNA molecules of defined nucleotide sequence has been around for many years, although Venter et al. deserve credit for the lengths to which they have taken this process. In this respect, the JCVI team (which includes molecular biologists Hamilton Smith, a Nobel Laureate, and his highly-respected colleague, Clyde Hutchison III) may be the possessors of a unique level of skill.
Impressively, Venter was able to simultaneously maintain that the new results are a landmark (a position also suggested in the article by Wade in which Venter was quoted) thereby justifying the time being devoted to discussing them, while criticizing the hype surrounding the study in various media outlets. This balancing act is certainly a major advance in self-promotion, and it is also one of the most impressive examples to date of how one organism can exploit the genes of another for objectives in the realm of public relations. Who knew that the genome of Mycoplasma mycoides could confer such an effective marketing phenotype? Does anyone need further proof of the context-dependence of gene function?
Given the brief time on the show that Dr. Baltimore was allotted, he did not have time to address some of the more substantive issues. But the scale of the buzz around the JCVI paper was sufficient to cause the arch-rival of Science, Nature, to publish online comments by multiple individuals with credentials relating to the science or the supposed ethical or societal aspects of the new findings. Jim Collins, a noted practitioner of synthetic biology at Boston University, offered a few key observations. For example, he noted that "it is very hard to design even a two-gene network that performs in the way that you would like." So the notion that anyone could design a new genome from scratch, as opposed to mostly copying an existing genome and tweaking it a bit, is difficult to take seriously in the foreseeable future.
As David Baltimore suggested at the end of the interview with Venter and the other guests, predictions about precisely where future scientific and technological developments will lead are inherently unreliable. It is impossible to say whether the latest results from JCVI will pave the way to fantastic and useful new technological capabilities or whether they will turn out to be an interesting but relatively inconsequential sidelight. Regardless of which outcome ensues, media claims of a "breakthrough" are either premature or wrong.
The opinions expressed above do not reflect official views of the institutions with which I am affiliated.
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