Transcriptomic screen to identify genes regulated by IP3R in Drosophila third-instar larval nervous system

Organisms need to co-ordinate growth with development particularly in the context of nutrient availability. Thus, multiple ways have evolved to survive extrinsic nutrient deprivation during development. In the holometabolous insect Drosophila, growth occurs during larval development.  Larvae are therefore critically dependent on nutritional inputs for pupariation. Post critical weight however, they pupariate even when starved. How nutrient availability is coupled to the internal metabolic state for the decision to pupariate in not well understood and needs better understanding. Wild type larvae, when subjected to nutrient deprivation as mid-third instar larvae, pupariate and also emerge as adults, even though smaller than normally fed ones (Jayakumar et al., 2016; Megha and Hasan, 2017). A recent study (Jayakumar et al., 2016) identified a neuronal circuit that enables wild-type larvae to survive protein deprivation and pupariate. IP3R function in a subset of glutamatergic neurons is a crucial part of the circuit. However, the cellular role of IP3R in these neurons is not understood. In Drosophila neurons, the IP3R causes and facilitates store-operated calcium entry (Chakraborty et al., 2016; Venkiteswaran and Hasan, 2009). Thus it is likely, that the IP3R also regulates expression of genes that regulate this phenomenon. In this study, we have compared the gene expression profiles of control and itpr knockdown larval brains to identify genes that act downstream of the IP3R to regulate pupariation under nutrition stress. mRNA sequencing from three biological relicates of control and two biological replicates of IP3R knockdown third instar larval brains