title: Locomotor activity rhythm in Drosophila melanogaster after 600 generations in an aperiodic environment.
abstract: The locomotor activity rhythm of flies from four populations of Drosophila melanogaster, maintained under constant light for more than 600 generations, was recorded in continuous light (LL) and continuous darkness (DD) using four different protocols. The main objective behind these experiments was to estimate the proportion of flies exhibiting circadian rhythm of locomotor activity in LL, and to investigate whether this could be increased by subjecting the flies to various light regimes. About 26% of the flies exhibited a circadian rhythm of locomotor activity in LL, and the proportion increased to about 48% after an exposure to 12 h of darkness. About 77% of the flies exhibited a circadian locomotor activity rhythm in DD. Persistence of circadian locomotor activity rhythm in a considerable proportion of these flies suggests an intrinsic adaptive value to possessing circadian rhythmicity, derived, perhaps, from the need to synchronise various processes within the organism.
authors.affiliation: Evolutionary Biology Laboratory, Evolutionary and Organismal Biology Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, PO Box 6436, Jakkur, Bangalore 560 064, India.
authors.forename: V
authors.initials: V
authors.lastname: Sheeba
authors.forename: M K
authors.initials: MK
authors.lastname: Chandrashekaran
authors.forename: Amitabh
authors.initials: A
authors.lastname: Joshi
authors.forename: Vijay Kumar
authors.initials: VK
authors.lastname: Sharma
mesh_terms: D000818:Animals; D004331:Drosophila melanogaster / Q000502:physiology*; D004777:Environment; D009043:Motor Activity / Q000502:physiology*; D010507:Periodicity