If you’re a male fruit fly looking for a mate it’s important to have the right comb. Not for your hair, but on your legs. The picture on the left is a close-up of a male fruit fly’s front leg, showing specialised dark, sturdy bristles known as sex combs. These help the male to grip onto a female while mating. Researchers have discovered a short stretch of DNA that acts as a genetic ‘switch’, turning on a gene called sex combs reduced (scr) at the right time and place during fly development to create the combs. Flies lacking one copy of the switch have smaller sex combs than usual (middle) while flies missing two copies have none at all (right), similar to female flies. Figuring out how these switches control genes like scr differently in males and females is shedding light on the complex genetic circuits that govern animal development.
Written by
BPoD stands for Biomedical Picture of the Day. Managed by the MRC Laboratory of Medical Sciences until Jul 2023, it is now run independently by a dedicated team of scientists and writers. The website aims to engage everyone, young and old, in the wonders of biology, and its influence on medicine. The ever-growing archive of more than 4000 research images documents over a decade of progress. Explore the collection and see what you discover. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.
BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.