Transcriptomics supports local sensory regulation in the antennae of the kissing bug Rhodnius prolixus

Abstract

Rhodnius prolixus has become a model for revealing the molecular bases of insect sensory biology due to the publication of its genome, its well characterized behavioural repertoire and the advent of NGS technologies. Gene expression modulation underlies behaviour-triggering processes at peripheral and central levels. Still, the regulation of sensory-related gene transcription in sensory organs is poorly understood. Here we study the genetic bases of plasticity in antennal sensory function, using R. prolixus as an insect model. Antennal expression of neuromodulatory genes such as those coding for neuropeptides, neurohormones and their receptors was characterized by means of RNA-Seq. New nuclear receptor and takeout gene sequences were identified for this species, as well as those of enzymes involved in the biosynthesis and processing of neuropeptides and biogenic amines. We report a broad repertoire of neuromodulatory and endocrine genes expressed in antennae and suggest that they modulate sensory neuron function locally. Diverse neuropeptide-coding genes showed consistent expression in the antennae of all stages studied. Future studies should characterize the contribution of these modulatory components acting over antennal sensory processes to assess the relative contribution of peripheral and central regulatory systems on the plastic expression of insect behaviour.