"A part of what's missing is some of the 'junk' DNA -- the recognizable repetitive content of the chicken genome is only about 10 percent as compared to about 50 percent for humans," says lead author LaDeana Hillier, senior research scientist at the GSC.
Scientists identified a chicken gene for interleukin 26, an important immune response protein only previously seen in humans. Researchers hope that further study of the chicken's immune system will lead to the development of better ways to control the spread of viruses, such as the bird flu in Asia. These viruses sometimes jump across species and infect humans.
"With both the human and the chicken genome sequences completed, we can ask more questions about what types of resistance to viral infections and other pathogens are possible for humans and chickens," Wilson says.
The chicken has traditionally been regarded as having a poor sense of smell, but an assessment of the number of smell receptors in the chicken genome has scientists reconsidering. The total number of receptors doesn't put the chicken in the same league as olfactory champions like the dog or the mouse, but it may place the chicken's sense of smell on a par with the human sense of smell. However, a search for taste receptors turned up relatively few results, suggesting chickens have a poor sense of taste.
By function, one area of strong chicken-to-human similarity was in genetic sequences related to early development. Several developmental genes, including genes linked to disorders that cause limb loss or deformity, were found in what the authors call ultraconserved regions--large, identical regions of DNA found in the genomes of chickens, mammals and humans.
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Contact: Michael C. Purdy
purdym@wustl.edu
314-286-0122
Washington University School of Medicine
8-Dec-2004