Seasonal Adaptation of a Circadian Clock

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DESCRIPTION (provided by applicant): This application is a competitive supplement to a recently awarded grant, 2 R01-NS42088. The overall goal of 2 R01-NS42088 is to understand how a circadian pacemaker accommodates new phase alignments in response to seasonal changes in ambient temperature and day length (photoperiod). A major foundation for the proposed specific aims is based on our prior work showing that the thermosensitive and photosensitive splicing of the 3'-terminal intron from the D. melanogaster period (per) RNA (termed dmpi8; D. melanogaster dper intron 8) acts as a multi-modal "seasonal sensor" conveying calendar information. We also showed that the norpA (no receptor potential A) gene encoding phospholipase C (PLC?), modulates the temperature and clock control of dmpi8 splicing efficiency. These findings identified a novel non-photic role for norpA. We proposed to determine how temperature, light, clock factors and NORPA/lipid metabolism co-regulate the splicing efficiency of dmpi8, and the contribution of this molecular event to seasonal adaptation in rhythmic behavior. Herein, we are requesting additional funds to purchase much needed equipment that is critical for progress on the approved specific aims and will significantly enhance the scope of the project. Major experimental strategies for this project involve measuring RNA levels, luciferase activity and Drosophila locomotor activity rhythms. Recent events not anticipated in the original application also offer novel possibilities to expand the scope of the specific aims. For example, we will evaluate newly described temperature-preference mutants for alterations in seasonal adaptation. However, our current capabilities in pursuing key objectives are severely limited. To enhance our research capabilities we request funding to purchase the following instruments; (1) Real-Time PCR system, (2) Microplate luminometer, (3) Environmental incubators and (4) Locomotor activity monitors. In addition, we request salary support for a Research Technician who will devote 100% effort to this proposal (currently devoting 50% effort). The equipment and personnel requests will have a marked impact on our studies aimed at understanding seasonal adaptation of clock function and how norpA participates in calibrating molecular and behavioral thermoresponses in D. melanogaster.