LD/DD time course of cn bw Drosophila

Mechanisms composing Drosophila's clock are conserved within the animal kingdom. To learn how such clocks influence behavioral and physiological rhythms, we determined the complement of circadian transcripts in adult Drosophila heads. High-density oligonucleotide arrays were used to collect data in the form of three 12-point time course experiments spanning a total of 6 days. Analyses of 24 hr Fourier components of the expression patterns revealed significant oscillations for 400 transcripts. Based on secondary filters and experimental verifications, a subset of 158 genes showed particularly robust cycling and many oscillatory phases. Circadian expression was associated with genes involved in diverse biological processes, including learning and memory/synapse function, vision, olfaction, locomotion, detoxification, and areas of metabolism. Data collected from three different clock mutants (per0, tim01, and ClkJrk), are consistent with both known and novel regulatory mechanisms controlling circadian transcription (Claridge-Chang et al., Neuron. 2001 Nov 20;32(4):657-71). For more information see also http://biorhythm.rockefeller.edu Keywords: Time course cn bw flies that had been kept in a 12-hr light/ 12-hr dark cycle for three days were harvested every four hours during an additional light/dark day (ZT) and a subsequent day in constant darkness (CT). Relative to Zeitgeber time 0 (ZT0) as the time of lights on during the LD cycle and Circadian time 0 (CT0) as the time corresponding to subjective lights-on during freerun in DD, time courses were collected in a ZT4- ZT8-ZT12-ZT16-ZT20-ZT24-CT4-CT8-CT12-CT16-CT20-CT24 schedule. Heads were isolated by breaking up frozen flies and passing them through a set of sieves. RNA was prepared using Rnazol (Tel-test) or Trizol (Life Technologies) extraction. Additional purification of the RNA samples was achieved by applying them to Rneasy columns (Qiagen). Biotin-labeled cRNA probe was generated from 25 μg of purified RNA and hybridized as described previously (Claridge-Chang et al., Neuron. 2001 Nov 20;32(4):657-71). For more information see also http://biorhythm.rockefeller.edu