SIMULATIONS OF FREE-RUNNING RHYTHMS, LIGHT ENTRAINMENT AND THE LIGHT-PULSE PHASE RESPONSE CURVES FOR THE LOCOMOTOR-ACTIVITY RHYTHM IN PERIOD MUTANT OF DROSOPHILA-MELANOGASTER

A single oscillator feedback model, originally developed to account fo r the circadian behaviour of the nocturnal insect, Hemideina thoracica , has been adapted to simulate some of the properties of the locomotor rhythms of Drosophila melanogaster, in particular the responses of th e locomotor activity rhythms of the wild-type and period mutants to si ngle light pulses and light entrainment. These simulations are achieve d by variations in per transcription and translation rates, the time d elay in the feedback loop, and degradation rates of the oscillating pr otein. The model is analogous to the word models of the mechanisms dev eloped from the molecular studies of the Drosophila circadian system. (C) 1997 Academic Press Limited.