March 1, 2007
UW-led studies featured in the journal Genome Research
The findings of two UW genome sciences research teams — one studying the genetics of the gibbon, and another examining a mechanism to allow for alternative readings of DNA — were featured in the February issue of the journal Genome Research.
A group led by Philip Green, professor of genome sciences and a Howard Hughes Medical Institute investigator, found a mechanism that may explain genetic diversity and evolution in higher organisms. The genetic tool, known as an alternative promoter, can cause a particular gene to produce more than one kind of protein, or produce the same protein at different times or in different tissues. The alternative promoter helps organisms get additional functions out of one gene, which may explain why a higher organism like a human can have about the same number of genes as a lower organism like a roundworm, yet be far more complex.
Green and his colleagues compared promoters in the human genome to those in the mouse genome, and used a new statistical tool to identify alternative promoters. A promoter tells specialized enzymes where to start reading DNA to produce a particular protein, and an alternative promoter is active at a different time or in a different tissue, or can tell the enzymes to start reading DNA at a different point on the genome.
The researchers found that about 40 percent to 50 percent of human and mouse genes have alternative promoters, which is a larger percentage than previously thought. The data suggest that alternative promoters are critically important to the functioning of higher organisms.
The February issue of Genome Research also featured a study led by Evan Eichler, associate professor of genome sciences and an HHMI investigator. Eichler and his colleagues examined the scrambling of the genome of the gibbon, a non-human primate. The genomes of humans and other primates closely resemble those of their ancestors, but the gibbon genome seems to have been more rapidly rearranged during the evolution of that species.
The researchers conducted the most detailed study so far of the chromosomal breaks and rearrangements that have changed the gibbon genome over time. Research on this process could help us better understand how evolution affects the genome, and may also explain how these chromosomal changes relate to chromosomal instability associated with cancer and other genetic diseases.
The research team also included scientists at the University of Bari, in Italy; Washington University, in St. Louis; and the Gibbon Conservation Center, in Santa Clarita, Calif.
