Chemoreception is a primitive sense universally employed by organisms for finding and
selecting food, rejecting toxic chemicals, detecting mates and offspring, choosing sites
for egg-laying, recognizing territories and avoiding predators. Chemosensory responses
are frequently modulated based on the internal environment of the organism. An
organism’s internal environment undergoes regular changes in anticipation and in
response to daily changes in its external environment, e.g., light-dark cycle. A resettable
timekeeping mechanism called the circadian clock internally drives these cyclical
changes with a ~24 hour period. Using electrophysiological, behavioral and molecular
analyses, I tested where and how these two conserved processes, viz., the circadian
timekeeping mechanism and the chemosensory pathway, intersect each other at
organismal and cellular levels.
The presence of autonomous peripheral oscillators in the chemosensory organs of
Drosophila, prompted us to test whether chemosensory responses are under control of
the circadian clock. I found that local oscillators in afferent (primary) chemosensory
neurons drive rhythms in physiological and behavioral responses to attractive and
aversive chemical signals. During the middle of the night, high level of G proteincoupled
receptor kinase 2 (GPRK2), a clock controlled signaling molecule present in
chemosensory neurons, suppresses tastant-evoked responses and promotes olfactory
responses. G-protein mediated signaling was shown to be involved in generating optimal
response to odorants. Multifunctional chemosensory clocks exert control on feeding and
metabolism. I propose that temporal plasticity in innate behaviors should offer adaptive
advantages to flies.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2011-05-9095 |
| Date | 2011 May 1900 |
| Creators | Chatterjee, Abhishek |
| Contributors | Hardin, Paul |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | thesis, text |
| Format | application/pdf |
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