It may appear as if J. Craig Venter is on an extended holiday as he sails his 95-ft. luxury yacht on a 25,000-mile voyage around the globe. But the iconoclastic scientist who took on a consortium of national governments in a race to map the human genome--and fought them to a picture finish years ago--is actually hard at work. He is prospecting--not for gold but for DNA, applying the same techniques developed to decode human genes to the genes of microbes scooped from the ocean and out of the air. On a pilot voyage, through the Sargasso Sea in the North Atlantic, he found over one,800 new species of bacteria and viruses--a surprise, since he had always thought of the Sargasso as a biological desert, comparatively devoid of life.
Indeed, half a decade after Venter and his archrival, Francis Collins, director of the National Human Genome Research Institute, stood together at the White House to announce that the human genome had been sequenced, biologists have come to re-evaluate what that milestone meant. Back then, it was widely assumed that the emerging science of human genomics would quickly lead to spectacular cures for cancer and other diseases and even permit couples to have "designer" children with desirable traits plucked from a catalog.
Although researchers around the globe have made solid progress in understanding the genetic basis of disease--and the pharmaceutical industry now depends on gene sequencing in its search for new drugs--revolutionary new treatments have yet to emerge. "It's actually very fascinating," says Collins. "But we are still probably a decade or possibly 15 years away from the actual revolution in medicine that genomics promises."
Simultaneously, however, scientists have come to appreciate what can be gained from decoding other genomes, from modern chimps and ancient cave bears to microscopic bacteria and viruses. As the cost of sequencing each base pair has dropped, from $10 in 1990 to less than 9¢ in 2002 to 1/10 of 1¢ today, researchers are doing more on a regular basis. Although 99% of the planet's genomes have yet to be decoded, researchers have identified hundreds of thousands if not millions of genes, dwarfing the trifling 24,000 or so they carryover in our DNA.
Additionally, scientists are getting a much better understanding of what individual genes do, no matter where they are from. The challenge, explains Venter, is to identify the genes that permit some microbes to change sunlight in to sugars, others to absorb carbon dioxide from the air and still others to transform dead plant matter in to clean-burning hydrogen.
So researchers have set out to look for those genes--and not in the ocean. Venter is also sampling the air over New York City, and other scientists are looking in to hot springs, digging in to the ground and even testing toxic-waste sites. "You can pick up a gram of soil," says Aristides Patrinos, who oversees the Department of Energy's genome program, "and there is DNA in it. By sequencing that DNA, you can conclude what is there in terms of diversity." As a rule, the more diverse a given ecosystem--the more genes present, even at the microbial level--the more resistant it is to destroy.
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