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The tremendous potential of these recombination techniques was not lost on the scientists. They reasoned that if the appropriate genes could be successfully inserted into E. coli, they could turn the bacteria into miniature pharmaceutical factories. The tiny creatures could churn out great quantities of insulin for diabetics (now obtained from the pancreases of pigs and other animals), clotting factor for hemophiliacs (currently both scarce and expensive), vitamins and antibiotics.
Re-engineered bacteria could have many other tasks. Scientists are already considering creation of special nitrogen-fixing bacteria, which would live in roots of crops that now do not have them, thus making it unnecessary to fertilize fields. A General Electric researcher has already added plasmids to create an experimental bug that produces enzymes capable of degrading a wide range of hydrocarbons; an organism engineered by recombinant DNA might some day be used to clean up oil spills. (Even this scheme alarms some opponents of the new research. They fear that a bug designed to gobble up oil spills might get into a pipeline or the fuel tanks of a jet in flight. Jokes one observer: "Some day you may have to worry about your car being infected.")
Most important, recombinant techniques are of enormous help to scientists in mapping the positions of genes and learning their fundamental nature. Stanley Falkow, a University of Washington microbiologist, recently used the method to isolate two toxin-producing bacterial genes that cause diarrhea in humans and livestock. This discovery may lead, in time, to a vaccine against the disorder. But far greater biological bonanzas are in the offing. After three decades of intense study, only one-third of E. coli's 3,000 to 4,000 separate genes have been identified. Higher organisms are much more complex. Humans, for example, have hundreds of thousands of genes. Trying to find out what each of them does has stymied scientists. But if human genes could be transplanted, one at a time, into E. coli and replicated in wholesale amounts, researchers would for the first time have great enough quantities of genes and their products to analyze them fully. Eventually, the genes on all 46 human chromosomes could be precisely located and studied. Not the least of the benefits might be a vastly increased understanding of the molecular basis of disease —especially cancer, which seems to occur when the cell's genetic machinery goes awry.
No one has given more thought to Andromeda-strain scenarios than the scientists who most strongly support the new research. Indeed, it was their own caution that first brought these possibilities before the public. In the summer of 1971, while lecturing on the safe handling of cancer viruses at James Watson's Cold Spring Harbor Laboratory on Long Island, a young cancer researcher named Robert Pollack learned from a visiting scientist that her boss at Stanford Medical Center planned a novel experiment. He hoped to insert a monkey virus, SV40, into E. coli. Although the virus seems harmless enough in its original hosts, it can cause tumors when injected into lab animals; it also turns laboratory cultures of human cells cancerous, although there is no evidence that it can cause cancer in people.