The scientists found that a mutated fruit fly gene controlling hearing and the mutated human counterpart gene both produced similar consequences: hearing loss as well as limb deformities and genital abnormalities. The mutated human gene is responsible for a disorder called Townes-Brocks' syndrome. The unexpected finding was published in the Proceedings of the National Academy of Sciences Online (Sept. 2, 2003).
"We were very surprised to learn about this specific genetic similarity," said Grace Boekhoff-Falk, PhD, associate professor of anatomy, who led the study. "Developmental biologists have known that there are remarkable parallels between fruit fly and human genetics, but the parallels have been restricted to tissues and organs that existed before the evolutionary divergence of vertebrates and invertebrates, which occurred more than 600 million years ago."
Sensing mechanisms that helped ancient organisms function were thought to exist before that divergence, Boekhoff-Falk explained, but not the ability to hear. Until now, the conventional wisdom has been that hearing evolved separately in vertebrates and invertebrates. "Our data supports the novel idea that hearing already existed 600 million years ago," she said.
The fruit fly (Drosophila melanogaster) has been the object of scientific study for a century, providing fundamental information on the way genes are transmitted and the effects of genetic mutations. In the past 15 years or so, it has become clear that many genes occurring in humans are also found in fruit flies.
Some six years ago scientists were excited to find that the same gene regulates ey
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Contact: Dian Land
dj.land@hosp.wisc.edu
608-263-9893
University of Wisconsin-Madison
9-Oct-2003