Action potential mutations stop a biological clock in Drosophila.

The Drosophila melanogaster male produces a species-specific courtship song by wing vibration. The most conspicuous feature of the song is a series of pulses with a 30-40-ms interpulse interval (IPI) which oscillate in wild-type males with a period of 50-60 s. This short-term biological rhythm in IPI is influenced by several gene mutations at the period (per) locus, which alter the normal 24-h free-running period of the circadian clock and have corresponding effects on the song cycle. The present study reveals that, under restrictive conditions, temperature-sensitive mutations which affect neuronal membrane excitability seem to stop the biological clock underlying the fruitfly's song rhythm.