Geneticists Identify 'Master Switch' That Causes Female Flies To Behave Like Males
Source: Stanford University
Date: 2005-06-16
"Turning on a single male-specific gene produces a female fruit fly that displays male courtship behaviors: chasing other females, tapping their abdomens and performing wing-beating love serenades. The results, published in the June 15 online edition of the journal Nature, show that a single gene can determine how females and males detect and respond differently to sexual cues.
'In these experiments we see all the steps of the male courtship ritual you could physically expect a female fly to do,'' says Bruce S. Baker, the Dr. Morris Herzstein Professor in Biology at Stanford and co-author of the study. ''It's a male's behavioral circuitry in a female body.'
Baker and Stanford graduate student Devanand S. Manoli and their collaborators at Brandeis and Oregon State universities focused on a gene known as fruitless-one of approximately 13,000 genes in the DNA of the common fruit fly, Drosophila melanogaster. The three laboratories had previously discovered that fruitless is the master gene controlling the male fruit fly's elaborate six-step courtship ritual. Last year they showed that disabling the fruitless gene in a tiny group of cells in the brain of a male fruit fly was enough to prevent successful mating, by turning him into a bumbling, ineffective suitor.
In the new study, researchers asked whether the fruitless gene would be enough to elicit male courtship behavior in female flies. They activated the gene in neural cells in the female fly's brain and sensory organs. When paired with a virgin female fruit fly, the masculinized females showed male courtship behavior: chasing the female fly and then tapping her on the abdomen. When a masculinized female was placed with a male, she responded to his advances with masculine rejection behavior-wing flicking and kicking-rather than the upturned posterior that is the normal female rejection response.
http://www.sciencedaily.com/releases/2005/06/050616062457.htm************************************************************
Could we be closing in on a genetic basis for homosexuality? One can only hope.
Jokerman