The journal PNAS has this week published an open access article by the Synthetic Biology Group lead by Craig Venter (the founder of the commercial "rival" to the publically-funded human genome project).
One of the objectives of Venter's group is to identify the smallest possible set of genes required to sustain life. By knocking out genes one by one and assessing the effect of such deletions, they hope to derive a minimal "component list" for a living cell. As they state in the introduction to the article, "One consequence of progress in the new field of synthetic biology is an emerging view of cells as assemblages of parts that can be put together to produce an organism with a desired phenotype. That perspective begs the question: "How few parts would it take to construct a cell?" In an environment that is free from stress and provides all necessary nutrients, what would constitute the simplest free-living organism? This problem has been approached theoretically and experimentally in our laboratory and elsewhere."