And finally, our gene of the month is Fruitless. Although it sounds like a bit of a lost cause, the Fruitless gene has attracted plenty of interest - not to mention controversy - over the years. In purely biochemical terms, Fruitless encodes a type of protein known as a ‘transcription factor’, which can switch other genes on, but it’s only when you look at its biological role that things get really interesting, because male fruit flies with faulty Fruitless have problems getting down to mating with female flies - in fact, they don’t seem very interested in the ladies at all, with some mutants preferring to go for the boys. And female flies with faulty Fruitless tend to behave more like males. Fruitless also pops up in mosquitoes and other insects, where it’s involved in sex determination
In fact, the gene’s name was originally “Fruity” - a slang term for gay - but it was switched as public attitudes to homosexuality became more enlightened. But while much has been made of Fruitless in the media, with speculation about whether the rules of human love and sexual orientation can be inferred from fruit fly genetics, humans don’t actually have an obvious version of the gene. So that kind of conjecture is probably as fruitless as the gene itself.