Word: long
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Dates: during 1990-1999
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With tons of soft tissue on ice, geneticists have no shortage of mammoth DNA to play out their fantasy: tweeze a bit of it out, insert it into the ovum of an elephant--a close living cousin--and implant the embryo in the elephant's womb. Before long, a woolly bundle should appear...
That's the hope, but it's a long shot, since even frozen DNA tends to deteriorate over time. "No matter how well preserved old DNA looks," says biologist Rob DeSalle of the American Museum of Natural History in New York City, "it's probably...
...scientists offered what could be the first really strong ray of hope in their struggle against this relentless killer. In a report in the journal Science, the gene-splicing wizards at Amgen, one of biotechnology's most successful companies, announced that they had succeeded in identifying and isolating a long-sought enzyme--a so-called protease--that may play a key role in creating the biochemical chaos in the brain that causes Alzheimer...
...elusive enzyme could finally offer a target at which drug designers could aim their medications, just as they currently use protease inhibitors to block the activity of the AIDS virus. That potential target is called beta-secretase. It had long been postulated to act as a chemical scissors that helps snip away pieces of excess protein protruding from brain cells, thereby creating the debris that gathers into the toxic plaques called amyloid. The accumulation of these fibrous clumps in the brain of Alzheimer's patients is the likeliest reason for their inexorable decline...
...those who entered the race was molecular biologist Martin Citron. In 1997, shortly after he moved from Harvard to Amgen, in Thousand Oaks, Calif., he and his team began a long, painstaking elimination process by inserting active human genes, in strings of 100 at a time, into living bacterial cells. When the team found cells making more amyloid protein than might have been expected, it narrowed the strings to 20 genes and repeated the process. Finally, the Amgen team zeroed in on the single gene responsible for producing the extra amyloid. Having found the culprit, the researchers went...