We humans have more in common with fruit flies
than we might realize, and that's why research on these tiny insects
can yield valuable clues about human genetics, illnesses and a wide
range of social interactions. Researchers have even found that jilted
male fruit flies turn to drink.
Scientists at the University of California, San Francisco (UCSF) discovered that when male fruit flies are rejected by female fruit flies they are driven to excessive alcohol consumption
and will drink far more than their sexually satisfied peers. They also
discovered that a tiny molecule in the fly's brain, called neuropeptide F, governs this behavior. Neuropeptides
are a highly diverse class of signal molecules in the brain. The UCSF
experiments showed that rejected male lies, whose brain levels of
neuropeptide F were lowered, sought alternative rewards by drinking to
intoxication when given access to alcoholic and non-alcoholic liquids.
Successfully mated male flies, who had higher levels of neuropepetide F
in their brains, were less likely to choose the intoxicant.
Ulrike Heberlein, who led the UCSF research and who is now scientific program director at the Janelia Farm
research campus of the Howard Hughes Medical Institute has noted the
research found a connection between the flies and mammals for a social
behavior influenced by brain chemistry. It turns out that a similar
human molecule, neuropeptide Y, may also be associated with social triggers that drive people to abuse alcohol and drugs.
Now scientists studying fruit flies are learning more about the brain activity that underlies male aggression. A New York Times story by James Gorman describes research by David J. Anderson,
a California Institute of Technology neuroscientist who is running what
the story calls a fruit fly fight club. He and colleague are studying
the role of the neuropeptide tachykinin
in male aggression. When neurons that produce tachykinin are silenced,
researchers were able to decrease aggression in the files. The emergence
of tachykinin is very interesting, the story says, because mammals have
several different kinds of tachykinin, some of which have been
associated with aggression in rodents and may have a variety of roles in
human brain function. While the implications for humans is unclear, Dr.
Anderson told The Times that "studying aggression in fruit flies can actually teach us something about some of the molecules that control aggression."
Researchers have known for some time that humans and Drosophila fruit flies have many of the same genes
and use them in the same way. Many known human diseases have
recognizable matches in the genetic code of the fruit fly. A University
of Glasgow scientist studying kidney stones produced kidney stones in fruit flies-and
noted that unlike humans, the flies didn't seem pained by them. Other
researchers have noted that genes and pathways that regulate fruit fly life spans seem closely parallel to the genes that underlie human longevity.
The poet William Blake had all life, even tiny insects, in mind when he wrote "The Fly" in his Songs of Experience,
His poem, in part, "Am I not/A fly like thee?/ Or art not thou/ A man
like me?/For I dance,/ And drink, and sing,/ Till some blind hand/ Shall
brush my wing."
Read The New York Times story here. A UCSF news story
explains how scientists discovered the link between fruit fly sex,
their altered brain chemistry, and links to a propensity for