Flying insects face the challenge to be up in the air. To stay airborne they need to oscillate their wings at frequencies up to 1000 times per second. These fast oscillations are powered by specialized flight muscles that contain a particular fibrillar organisation of their contractile apparatus and hence differ from all other muscles. In vinegar flies (Drosophila
) the researchers identified a developmental switch gene, spalt
, which induces the formation of these specialised flight muscles. Spalt
mutants are flightless: their flight muscles have lost all their special properties.