mutants in drosophila trpc channels reduce olfactory sensitivity to carbon dioxide突变体在果蝇trpc通道减少二氧化碳的嗅觉灵敏度.pdfVIP

Mutants in Drosophila TRPC Channels Reduce Olfactory Sensitivity to Carbon Dioxide 1 1¤ 1 2 1 Farhath Badsha , Pinky Kain , Sunil Prabhakar , Susinder Sundaram , Raghu Padinjat , 1,3{ 1 Veronica Rodrigues , Gaiti Hasan * 1 National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, Karnataka, India, 2 Inositide Laboratory, Babraham Institute, Cambridge, United Kingdom, 3 Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra, India Abstract Background: Members of the canonical Transient Receptor Potential (TRPC) class of cationic channels function downstream of Gaq and PLCb in Drosophila photoreceptors for transducing visual stimuli. Gaq has recently been implicated in olfactory sensing of carbon dioxide (CO2) and other odorants. Here we investigated the role of PLCb and TRPC channels for sensing CO2 in Drosophila. Methodology/Principal Findings: Through behavioral assays it was demonstrated that Drosophila mutants for plc21c, trp and trpl have a reduced sensitivity for CO2. Immuno-histochemical staining for TRP, TRPL and TRPc indicates that all three channels are expressed in Drosophila antennae including the sensory neurons that express CO2 receptors. Electrophysiological recordings obtained from the antennae of protein null alleles of TRP (trp343) and TRPL (trpl302), showed that the sensory response to multiple concentrations of CO2 was reduced. However, trpl302; trp343 double mutants still have a residual response to CO2. Down-regulation of TRPC channels specifically in CO2