Patterns of Gene Expression in Drosophila InsP3 Receptor Mutant Larvae Reveal a Role for InsP3 Signaling in Carbohydrate and Energy Metabolism

BackgroundThe Inositol 1,4,5-trisphosphate receptor (InsP3R) is an InsP3 gated intracellular Ca2+-release channel. Characterization of Drosophila mutants for the InsP3R has demonstrated that InsP3-mediated Ca2+ release is required in Drosophila larvae for growth and viability. Methodology/Principal FindingsTo understand the molecular basis of these growth defects a genome wide microarray analysis has been carried out with larval RNA obtained from a strong InsP3R mutant combination in which 1504 independent genes were differentially regulated with a log2 of fold change of 1 or more and P3R mutants where growth defects were either suppressed by introduction of a dominant suppressor or rescued by ectopic expression of an InsP3R transgene in the Drosophila insulin like peptide-2 (Dilp2) producing cells. Conclusions/SignificanceThese studies show that expression of transcripts related to carbohydrate and amine metabolism is altered in InsP3 receptor mutant larvae. Moreover, from a comparative analysis of genes that are regulated in the suppressed and rescued conditions with the mutant condition, it appears that the organism could use different combinations of pathways to restore a ‘normal’ growth state.