EVANSTON, Ill. - A new Northwestern University study that advances the understanding of the genetics of hearing disorders will be published May 11 in the journal Nature. In an unusual collaboration of hearing science and molecular biology experts, researchers have cloned a gene, named after the musical notation presto, that is critical to the functioning of the outer hair cell, a sensory receptor cell unique to the inner ear of mammals.
Research teams under the direction of Peter Dallos, John Evans Professor of Neuroscience, and Laird D. Madison, M.D., assistant professor at the Center for Endocrinology, Metabolism and Medicine at the University's Medical School, have successfully cloned the gene Prestin which codes for a protein (prestin) that is an important molecular motor in the outer hair cell. Prestin is a new biological motor in mammals, joining the classical molecular motors kinesin, dynein and myosin, the latter being the protein that causes muscles to contract.
Roughly 25 million people in the United States are severely hard of hearing, and many of these deficits are related to the loss of outer hair cell function. In addition to the health implications of the prestin discovery, these tiny biocompatible motors could be a boon to the developing nanotechnology field.
"This is a landmark study," said Mario Ruggero, Hugh Knowles Professor of Hearing Sciences and head of the audiology and hearing sciences program, department of communication sciences and disorders, at Northwestern. "It identifies the molecular basis for the motile process that makes the outer hair cells of the mammalian cochlea unique and which may be responsible for the exquisite sensitivity of sound perception in humans."
It is widely believed that outer hair cells act as local mechanical amplifiers of the incoming sound vibrations, giving the mammalian ear its extraordinary sensitivity and frequency-resolving capacity. During amplification, the cylinder-
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