Fruit Fly Klutzes Give Clues to Human Hearing, Touch
March 23, 2000 (Boston) -- They would probably make lousy dance partners,
but a bunch of fruit flies so uncoordinated that they cannot even get food into
their mouths is providing scientists with evidence of a gene that controls how
sensations such as hearing, touch, and body position are conveyed to the brain.
The research is reported in the March 24 issue of the journal
And although it's a long conceptual leap from fruit fly to human, the
findings may help medical researchers understand and perhaps treat or prevent
certain inherited forms of deafness, suggest Richard G. Walker, PhD, and
colleagues from the University of California, San Diego.
Fruit flies are the workhorses of genetic laboratories, because all of the
genes that make the pesky little creatures what they are have been identified
and catalogued. Many of the genes, in fact, are similar to those found in
higher animals, including humans. Also, because fruit flies are born, grow up,
breed, and die within two months, scientists can study how changes in specific
genes in one generation of flies can affect their posterity for many
generations to come.
But what do flies with two -- make that six -- left feet have to do with the
realm of the senses? The answer has to do with the mechanisms that allow cells
in the body to respond to a physical or mechanical stimulus such as a touch or
a sound wave.
"Biologists have a pretty good idea of how chemicals work to signal
cells [with] odors, tastes -- things like that, and we have a very good idea
about the molecules involved in [responding] to light. We are virtually
clueless as to how mechanical stimuli are translated into signals in
cells," says Martin Chalfie, PhD, professor of biology at Columbia
University in New York, who reviewed the study for WebMD. "Mechanical
information is utilized by touch, hearing, balance, stretch, position, blood
pressure, [and is even] important in regulating the amount of bone that you
To see whether they could find a gene that controlled how sensing cells send
information to the brain, Walker and colleagues narrowed in on three strains of
flies that couldn't find their way out of a lab dish, let alone out of a paper
bag. The flies all had mutations in a specific gene that caused them to be so
uncoordinated that their first act as full-fledged adult flies was to fall into
their sticky food and die.
Although some genetic mutations are lethal, the flies died not because they
inherited a fatal defect but because they couldn't figure out where they were
or how to get food, which for normal fruit flies is as easy as falling off a
log. "If you take them and put them in a non-sticky environment such as a
piece of filter paper and you feed them, they'll probably live for a long
time," says Walker in an interview with WebMD.