Regulation of thermosensation by Sulfakinin receptors

Abstract

Temperature is a critical factor regulating various biological responses including behavior pattern and cellular metabolism. Most animals have abilities to track suitable temperature for their living, called thermotaxis, which is a consequence of specific neurobiological function, thermosensation. However, the molecular mechanisms of thermosensation are not clearly understood. Thus, I conducted screening to find molecules involved in the regulation of thermosensation. Consequently, I found that mutants for DSK (Drosulfakinin) ligand and one of two known receptors, DSK-D1 receptor, showed abnormal temperature preferences. DSK ligand is known to be enriched in CNS and suggested to act as hormones, modulators, or transmitters in CNS. To elucidate roles of these molecules in thermosensation, I generated loss-of-function mutants for two receptors for DSK ligand, DSK-D1 and DSK-D3, and using these new mutants, I confirmed similar results of temperature preferences with those from EP lines above. Consistently, the DSK-D1 receptor have low tolerance for high temperature. Interestingly, DSK-D1 and DSK-D3 receptors showed distinct expression patterns that DSK-D1 receptor was expressed mainly after early pupal period, while DSK-D3 receptor was expressed through whole developmental stages. In addition, using in situ hybridization, I found that DSK-D3 receptor was ubiquitously expressed during embryogenesis. Then, to determine spatial expression patterns for both DSK-D1 receptor and DSK-D3 receptor in CNS, I generated antibodies for these molecules. Using these antibodies, I found that DSK-D1 receptor was mainly expressed in specific glial cells in adult brain. Collectively, these results suggest that one of two DSK receptors, DSK-D1 receptor, mediates signal from DSK ligand to mediate thermosensation after pupal period at the specific region of adult brain.