For Fruit Flies, Turning Off a Gene Means Turning On the Same-Sex Love

Forget looking for a "gay gene": fruit flies, the favorite insects of geneticists for a century, need a particular gene to keep the males straight. A team of scientists led by Manyuan Long at the University of Chicago call it the sphinx gene, and it is present only in fruit flies. Long's grad student Wen Wang identified the gene back in 2002, and now two other former students, Hongzheng Dai and Ying Chen, have discovered its purpose. When Dai and Chen turned off the gene, the males looked and acted ordinary, at least until they were placed in each other's company. When that happened, the genetically engineered flies spent 10 times more time pursuing other males than normal fruit flies. Long says that the gene evolved about two million years ago to prevent male flies from inhibiting mating by spending too much time with each other. Dai and Chen's study ...