Patterns of gene expression in drosophila InsP 3 receptor mutant larvae reveal a role for InsP 3 signaling in carbohydrate and energy metabolism

Abstract

Background: The Inositol 1,4,5-trisphosphate receptor (InsP 3R) is an InsP 3 gated intracellular Ca 2+-release channel. Characterization of Drosophila mutants for the InsP 3R has demonstrated that InsP 3-mediated Ca 2+ release is required in Drosophila larvae for growth and viability. Methodology/Principal Findings: To understand the molecular basis of these growth defects a genome wide microarray analysis has been carried out with larval RNA obtained from a strong InsP 3R mutant combination in which 1504 independent genes were differentially regulated with a log 2 of fold change of 1 or more and P<0.05. This was followed by similar transcript analyses from InsP 3R mutants where growth defects were either suppressed by introduction of a dominant suppressor or rescued by ectopic expression of an InsP 3R transgene in the Drosophila insulin like peptide-2 (Dilp2) producing cells. Conclusions/Significance: These studies show that expression of transcripts related to carbohydrate and amine metabolism is altered in InsP 3 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. © 2011 Kumar et al.