tom

tom paulson::Something like 8 percent of the human genome, the entirety of our dna, comes from infection by viruses that can inject their genes into host cells retroviruses.
Hiv, virus that causes aids, is a retrovirus.
Rather, its genetic footprints, left by infections accomplished many eons ago, were identified with the recent sequencing of the entire chimpanzee genome, a project coled by the and completed in 2005.
Chimps and humans share something like 98 percent of the same dna.
Pan troglodytes is scientific lingo for chimp.
They had previously discovered a gene in humans that produced a powerful antiviral protein, but had been unable to find the virus it targeted.
Could this human antiviral protein have been what once protected humans from the ancient retrovirus?
Working with another fred hutchinson colleague, , they used the chimp gene sequences to reconstruct a small portion of the ancient retrovirus and tested it against the protein.
It came up a match.
The chimphuman genetic anomaly and the targetless protein were simultaneously explained.
Unfortunately, emerman said, this protein that worked so well to protect humans against the ancient virus now appears to make us more susceptible to hiv.
When they removed this protein from human cells, the fred hutchinson team discovered that resistance to hiv increased.
If there were some way to remove the gene that produces this protein from all our cells technically impossible today humans could, in theory anyway, be made more resistant to hiv.
Scientists have shown that hiv evolved from a very similar chimp retrovirus known as siv, simian immunodeficiency virus.
In tests, chimps are seldom made ill from hiv infection.
The difference in immunity to hiv between these genetically similar primates, chimps and humans, was for many years thought to hold some clue for an aids vaccine.