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 Fruit
Fly Homosexuality Study Likely To Prove Controversial
by 365Gay.com Newscenter Staff
Posted: December 10, 2007 - 8:00 am ET
(Chicago, Illinois) While the biological basis for homosexuality remains a mystery, a team of
neurobiologists says it may be closer to an answer.
The team led by University of Illinois at Chicago researcher David
Featherstone says it has discovered that sexual orientation in fruit flies is controlled
by a previously unknown regulator of synapse strength.
Armed with this
knowledge, the researchers claim they were able to use either genetic
manipulation or drugs to turn the flies' homosexual behavior on and off within
hours.
The research will appear in the January issue of Nature
Neuroscience the university said.
Featherstone, associate professor of biological sciences at UIC, and his
coworkers discovered a gene in fruit flies they called "genderblind,"
or GB. A mutation in GB turns flies bisexual.
Featherstone found the gene interesting initially because it has the unusual
ability to transport the neurotransmitter glutamate out of glial cells -- cells
that support and nourish nerve cells but do not fire like neurons do. Previous
work from his laboratory showed that changing the amount of glutamate outside
cells can change the strength of nerve cell junctions, or synapses, which play a
key role in human and animal behavior.
But the GB gene became even more interesting when post-doctoral researcher
Yael Grosjean noticed that all the GB mutant male flies were courting other
males.
"It was very dramatic," said Featherstone.
The GB mutant
males, he said, treated other males exactly the same way nonmutant male flies would treat a
female. They even attempted copulation Featherstone said.
Other genes that alter sexual orientation have been described, but most just
control whether the brain develops as genetically male or female. It's still
unknown why a male brain chooses to do male things and a female brain does
female things. The discovery of GB provided an opportunity to understand why
males choose to mate with females.
"Based on our previous work, we reasoned that GB mutants might show
homosexual behavior because their glutamatergic synapses were altered in some
way," said Featherstone. Specifically, the GB mutant synapses might be
stronger.
"Homosexual courtship might be sort of an 'overreaction' to sexual
stimuli," he explained.
To test this, he and his colleagues genetically altered synapse strength
independent of GB, and also fed the flies drugs that can alter synapse strength.
As predicted, they were able to turn fly homosexuality on and off -- and within
hours.
"It was amazing. I never thought we'd be able to do that sort of thing,
because sexual orientation is supposed to be hard-wired," he said.
"This fundamentally changes how we think about this behavior."
Featherstone and his colleagues reasoned that adult fly brains have
dual-track sensory circuits, one that triggers heterosexual behavior, the other
homosexual. When GB suppresses glutamatergic synapses, the homosexual circuit is
blocked.
Meanwhile, a new book by a
British anthropologist is likely to be equally controversial.
Desmond Morris, who previously
wrote The Naked Ape, claims in his new book The Naked Man that
some men are gay because they failed to break the 'boys
together' stage of childhood.
That claims Morris results in
gay men being more playful and experimental and leads to gays
being more artistic.
"Gays have in general made
a disproportionately greater contribution to life than nongays,"
he writes, pointing to gays like Socrates, Leonardo da Vinci,
Tchaikovsky, Cole Porter and Oscar Wilde.
©365Gay.com 2007
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