The long awaited announcement that the entire genetic material of a tiny microorganism was replaced with a chemical replica came late last week. The announcement was greeted by the global press with great fanfare. The cover of the May 22 issue of the Economist reads, "And Man Made Life: The First Artificial Organism and Its Consequences" -- illustrated with the famous Sistine Chapel Adam, modesty preserved by laptop, reaching heavenward to give life to new bacteria.
What was actually done and what does it mean? The chemical synthesis of an entire bacterial genome, a very long string of DNA, about a million units in length, is a significant technical achievement. The DNA molecule was stitched together by joining about one thousand smaller fragments each about one thousand units long. To assemble these in the correct order, without significant error, is a great feat of modern organic chemistry. It is the largest single molecule ever made. Now that it has been done, it can be done again with different genomes.
Step two was the replacement of a natural genome with the replica. This also ranks as a significant achievement. The natural defenses bacteria have to protect themselves from invading DNA had to be overcome. Done once, this, too, can be done again.
Has man indeed made life? I think not. The replica is indistinguishable in form and function from the original. Were it not for marker tags introduced into the replica DNA, there would be no difference at all. It is as if one were to create a copy of Michelangelo's David, accurate down to the last crack and imperfection except for the signature, and call it new. Is the organism so created useful? No more so than the original, most famous for being small, with no known use outside the laboratory.
Will this work open a new era of modern biology? Again unlikely. That door was opened some time ago with the advent of genetic engineering that allows functioning genes of one organism to be inserted into another (think of the human gene for insulin inserted in bacterium to produce the replacement hormone for diabetics), and more recently by mixing and matching the genes from many different species to create new useful biochemical pathways. For example, nine different genes, some from bacteria and some from plants, were spliced into yeast DNA to direct the production of an anti-malarial drug previously only obtainable from a tropical plant. Similar methods have already been used to ferment diesel and jet fuel. These techniques are part of a rapidly growing field I call "constructive biology," but now goes by the unfortunate name "synthetic biology."
Does this experiment raise new moral and ethical issues? This genie has long been out of the laboratory flask. For decades we have had the ability to genetically alter life forms to suit our purpose. The vast majority of applications have been for good: to heal the sick and feed the hungry. If the technology has been seriously misused, the results are hidden, shrouded in secrecy, perhaps in military laboratories. Yes, we must be vigilant as always, but these new results do not change the game.
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