Analysis of the chicken's telomeres, cap-like structures on the ends of chromosomes, revealed that they are more similar to human telomeres than rodent telomeres. Scientists believe telomeres shorten the DNA slightly every time a cell divides, eventually making it impossible for the cell to divide. This inability to renew through cell division is thought to be a primary component of the structural and functional breakdowns produced by aging.
Increased telomere similarity may mean that the chicken, already a valuable tool for study of the earliest stages of life, also will become useful for study of its final stages.
Wilson compares the chicken genome and other genomes to Rosetta Stones scientists are using to better understand the human genome. As life on Earth evolved over time, genes have been created, kept, discarded or deactivated, and reorganized. At the particular point in evolutionary time over which a species first develops, these processes may have changed a gene in ways that allow scientists to use it to get a better fix on the human version of the gene.
"For every human gene, there's a gene in another species that's going to be most helpful in understanding the human version," Wilson explains. "For some human genes, we might be able to learn more by looking at the genome of the mouse; for others, we might have to look at the version of the gene found in the chicken."
Based on their initial look at the chicken genome, scientists have suggested that they may need to alter the proposed starting point for as many as 2,000 human genes.
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Contact: Michael C. Purdy
purdym@wustl.edu
314-286-0122
Washington University School of Medicine
8-Dec-2004