Phenotypic variation in biting behavior associated with differences in expression of olfactory genes in the vector...

We evaluated miRNA and mRNA expression differences in head tissues between avid-biting vs. reluctant-biting Aedes albopictus (Skuse) females from a single population over a 20-min timescale. We found no differences in miRNA expression between avid vs. reluctant biters, indicating that translational modulation of blood-feeding behavior occurs on a longer timescale than mRNA transcription. In contrast, we detected 19 differentially expressed mRNAs. Of the 19 differentially expressed genes at the mRNA level between avid-biting vs. reluctant-biting A. albopictus, 9 are implicated in olfaction, consistent with the well-documented role of olfaction in mosquito host-seeking. Additionally, several of the genes that we identified as differentially expressed in association with phenotypic variation in biting behavior share similar functions with or are inferred orthologues of, genes associated with evolutionary variation in biting behaviors of Wyeomyia smithii (Coq.) and Culex pipiens (Lin.). A future goal is to determine whether these genes are involved in the evolutionary transition from a biting to a non-biting life history.