Varying Gene Expression in the Fat Body and Ovary of Diapausing Culex Pipiens

The Culex pipiens is a vector for the West Nile Virus and enters adult diapause, a programmed state of dormancy for surviving winter conditions. During diapause, mosquitoes undergo a variety of phenotypic changes, such as arrested development, lipid accumulation, and lifespan extension. The fat body and ovarian development were noted to be altered in diapausing Cx.pipiens and thus transcriptome profiling of the fat body and ovary was used to identify downstream genes that are involved in the formation of unique histone modification patterns that contribute to the diapause phenotype. Previously, RNA sequencing was used to identify notable genes. This portion of the research used quantitative RT-PCR to validate candidate genes that were identified from the RNA-seq data. It was found that 246 fat body genes and 328 ovary genes were upregulated in diapause mosquitoes. These genes are involved in lipid synthesis, yolk production, and the resistance mechanism, confirming the phenotypes associated with diapausing mosquitoes. qRT-PCR confirmed that the genes are upregulated in the fat body. Additionally, it was found that genes associated with histone methylation and demethylation are also differentially expressed in the fat bodies of diapause mosquitoes, such as the histone demethylation gene UTX which is upregulated in the fat body of diapausing mosquitoes.