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Series GSE3832

Query DataSets for GSE3832

Status

Public on Feb 03, 2006

Title

LD/DD time course of y w; tim01 Drosophila #2

Organism

Drosophila melanogaster

Experiment type

Expression profiling by array

Summary

Background. The transcriptional circuits of circadian clocks control physiological
and behavioral rhythms. Light may affect such overt rhythms in two ways: (1) by
entraining the clock circuits and (2) via clock-independent molecular pathways. In
this study we examine the relationship between autonomous transcript
oscillations and light-driven transcript responses
Methodology/Principal Findings. Transcript profiles of wild-type and arrhythmic
mutant Drosophila were recorded both in the presence of an environmental
photocycle and in constant darkness. Systematic autonomous oscillations in the
12-48 hr period range were detectable only in wild-type flies and occurred
preferentially at the circadian period length. However, an extensive program of
light-driven expression was confirmed in arrhythmic mutant flies. Many lightresponsive
transcripts are preferentially expressed in the adult compound eye
and the phospholipase C component of phototransduction, NO RECEPTOR
POTENTIAL (NORPA), is required for their light-dependent regulation.
Conclusions/Significance. Although there is growing evidence for the existence
of multiple molecular clock circuits in plants and fungi, Drosophila appears to
possess only one such system. The sustained photic expression responses
identified here are partially coupled to the circadian clock and may reflect a
mechanism for flies to modulate functions such as visual sensitivity and synaptic
transmission in response to seasonal changes in photoperiod.
Keywords: Time course

Overall design

y w; tim01 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 ZT2-
ZT6-ZT10-ZT14-ZT18-ZT22-CT2-CT6-CT10-CT14-CT18-CT22 schedule. Heads
were isolated by breaking up frozen flies and passing them through a set of
sieves. RNA was prepared using guanidine-thiocyanate extraction followed by
purification over a CsCl gradient. 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 (Wijnen H, Naef F, and Young MW, Methods Enzymol. 2005; 393: 341-365).
For more information see also http://biorhythm.rockefeller.edu

Contributor(s)

Wijnen H, Boothroyd C, Young MW

Citation missing

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Submission date

Dec 14, 2005

Last update date

Jul 06, 2016

Contact name

Herman Wijnen

E-mail(s)

hw3a11@soton.ac.uk