ILP1 mediates resource allocation for reproduction during the induction of diapause in culex mosquitoes.
In this study, we demonstrate that ILP1 plays a crucial role in balancing the mosquito's metabolic environment to modulate the reproductive cycle. Exposure of mosquitoes to diapause-inducing conditions led to a significant decrease in ILP1 levels, leading to reduced blood feeding, fat hypertrophy, arrested ovarian development. The inverse expression of ILP1 suggests that this gene regulates mosquito reproduction based on perceived environmental stimuli.  siRNA knockdown of ILP1 resulted in phenotypes similar to those observed in mosquitoes raised under diapause-inducing conditions. Transcriptome analysis revealed that numerous genes related to sucrose, fructose, mannose, linoleic acid glycerophospholipid and negative regulation of protein and amino acid metabolism together with genes involved in negative regulation of endopeptidase activity were significantly up-regulated across the gonotrophic cycle in ILP1-depleted mosquitoes. Metabolomic analysis indicated that many metabolites regulated by these genes in these metabolic pathways were also markedly accumulated when ILP1 is depleted. Consequently, we inferred that linoleic acid of carbohydrate metabolism and the ß-oxidation pathway cooperatively generate enough acyl-CoA, which enters the TCA cycle to provide energy for survival at the expense of reproduction during diapause induction. Hence, our study suggests that ILP1 plays an integral role in Culex mosquitoes by directing resource allocation for reproduction. Overall design: To investigate the the role of ILP1 in diapause induction, we characterised the expression of ILP1 at different mosquito growth stages, feeding state and under diapause inducing conditions We then knocked down ILP1 with siRNA primers by microinjection in order to investigate the role of ILP1 in ovarian arrest during diapause induction We then performed gene expression profiling analysis using the data obtained from RNA-seq of ILP1 depleted mosquitoes (siILP1) and negative control mosquitoes (NC). Comparative gene expression  profiling analysis was performed using RNA-seq data to identified differentially expressed genes in ILP1 depleted mosquitoes