Seasonal Adaptation of a Circadian Clock

Project Details

Description

DESCRIPTION (provided by applicant): The overall goal of this proposal is to
understand how a circadian clock (or pacemaker) accommodates new phase
alignments in response to seasonal changes in ambient temperature and daylength
(photoperiod), a topic that has received little attention from a molecular
perspective. This feature of circadian clocks has immense biological
significance because it enables organisms to (1) adopt optimal phase-alignments
between physiological and behavioral rhythms and the prevailing environmental
conditions, and (2) trigger seasonally appropriate responses. A major
foundation for the proposed specific aims in this application is based on our
recent published work [Majercak et al., (1999) Neuron, 24:219] showing that the
thermosensitive splicing of the 3-terminal intron from the D. melanogaster
period (dper) RNA (herein refereed to as dmpi8; D. melanogaster dper intron 8)
makes a major contribution to the preferential daytime activity of this species
during seasonally cold days. Recent findings indicate that whereas the splicing
efficiency of dmpi8 is stimulated by cold temperatures, light inhibits this
splicing event, demonstrating intricate multi-modal regulation. Our findings
suggest that the thermal and photoperiodic regulation of dmpi8 splicing acts as
a "seasonal sensor" conveying calendar information to the animal. In this
application we propose to determine how temperature and light co-regulate the
splicing efficiency of dmpi8. No only will these studies investigate a novel
effect of light on the D. melanogaster circadian clock but our recent findings
implicate a new role for the visual signal transduction cascade in the phase
control of activity rhythms driven from deep brain pacemaker cells. Moreover,
we will analyze the clockworks and behavioral rhythms in several Drosophila
species from a wide range of latitudinal gradients. These studies might reveal
a role for natural selection in the adaptation of circadian clocks to
geographical variations in seasonal climates. To accomplish these goals we
propose to take multifacted experimental strategies including in vitro
biochemical, tissue culture and whole animal approaches. With the recent
realization that the basic molecular logic underlying circadian clocks from a
wide variety of organisms, including humans, is conserved, it is anticipated
that although specific details will differ our investigation of how a circadian
clock integrates multiple environmental modalities will lead to general
principles that are applicable to a wide range of circadian systems.
StatusFinished
Effective start/end date7/15/016/30/15

Funding

  • National Institute of Neurological Disorders and Stroke: $128,363.00
  • National Institute of Neurological Disorders and Stroke: $330,138.00
  • National Institute of Neurological Disorders and Stroke: $332,281.00
  • National Institute of Neurological Disorders and Stroke: $354,569.00
  • National Institute of Neurological Disorders and Stroke: $340,448.00
  • National Institute of Neurological Disorders and Stroke: $263,245.00
  • National Institute of Neurological Disorders and Stroke: $354,910.00
  • National Institute of Neurological Disorders and Stroke: $330,818.00
  • National Institute of Neurological Disorders and Stroke: $262,979.00
  • National Institute of Neurological Disorders and Stroke: $320,652.00
  • National Institute of Neurological Disorders and Stroke: $386,250.00
  • National Institute of Neurological Disorders and Stroke: $336,875.00
  • National Institute of Neurological Disorders and Stroke: $262,422.00
  • National Institute of Neurological Disorders and Stroke: $262,704.00

ASJC

  • Medicine(all)
  • Neuroscience(all)
  • Signal Processing
  • Genetics
  • Biochemistry, Genetics and Molecular Biology(all)
  • Physiology
  • Cell Biology
  • Ecology

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