The maxillary palp of aedes aegypti, a model of multisensory integration

Authors: Bohbot, Jonathan; Sparks, Jackson; Dickens, Joseph

Submitted to: Insect Biochemistry and Molecular Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/15/2014
Publication Date: 3/20/2014
Citation: Bohbot, J.D., Sparks, J.T., Dickens, J.C. 2014. The maxillary palp of aedes aegypti, a model of multisensory integration. Insect Biochemistry and Molecular Biology. (48):29-39.

Interpretive Summary: Mosquitoes are attracted to their human or animal hosts from a distance by visual, temperature and chemical cues. While sensors for chemical and temperature cues were shown to reside principally on the antennae of the mosquito, the mouthpart maxillary palps were thought to have sensors mainly for detection of octenol and carbon dioxide, which are chemical attractants emitted in the breath of vertebrate hosts. Here we characterize the expression of genes in the maxillary palps of adult female mosquitoes and show that the palps have not only detectors for host chemicals, but also detectors for temperature. In addition to unraveling the genetic basis of sensory processing of female mosquitoes, our study provides potential molecular targets for use by entomologists and molecular biologists for disruption of mosquito behavior for the protection of humans and animals from these important disease vectors.

Technical Abstract: Female yellow-fever mosquitoes, Aedes aegypti, are obligate blood-feeders and vectors of the pathogens that cause dengue fever, yellow fever and Chikungunya. This feeding behavior concludes a series of multisensory events guiding the mosquito to its host from a distance. The antennae and maxillary palps play a major role in host detection and other sensory-mediated behaviors. Compared to the antennae, the maxillary palps are a relatively simple organ and thus an attractive model for exploration of the neuromolecular networks underlying chemo- and mechanosensation. In this study, we surveyed the expressed genetic components and examined their potential involvement with these sensory modalities. Using Illumina sequencing, we identified the transcriptome of the maxillary palps of physiologically mature female Ae. aegypti. Genes expressed in the maxillary palps included those involved in sensory reception, signal transduction and neuromodulation. In addition to previously reported chemosensory genes, we identified candidate transcripts potentially involved in mechanosensation and thermosensation. This survey lays the groundwork to explore sensory networks in an insect appendage. The identification of genes involved in thermosensation provides prospective molecular targets for the development of chemicals aimed at disrupting the behavior of this medically important insect.