Genome Investigations of Vector Competence in Aedes aegypti to Inform Novel Arbovirus Disease Control Approaches

Abstract

Dengue (DENV), yellow fever, chikungunya, and Zika virus transmission to humans by a mosquito host is confounded by both intrinsic and extrinsic variables. Besides virulence factors of the individual arboviruses, likelihood of virus transmission is subject to variability in the genome of the primary mosquito vector, Aedes aegypti. The "vectorial capacity" of A. aegypti varies depending upon its density, biting rate, and survival rate, as well as its intrinsic ability to acquire, host and transmit a given arbovirus. This intrinsic ability is known as "vector competence". Based on whole transcriptome analysis, several genes and pathways have been predicated to have an association with a susceptible or refractory response in A. aegypti to DENV infection. However, the functional genomics of vector competence of A. aegypti is not well understood, primarily due to lack of integrative approaches in genomic or transcriptomic studies. In this review, we focus on the present status of genomics studies of DENV vector competence in A. aegypti as limited information is available relative to the other arboviruses. We propose future areas of research needed to facilitate the integration of vector and virus genomics and environmental factors to work towards better understanding of vector competence and vectorial capacity in natural conditions.

Keywords: Aedes aegypti; dengue virus; functional genomics; genetic control; innate immunity; integrative approach; mosquito arbovirus interaction; transcriptome; vector competence.

Figure 1

Physical chromosome locations of anchor markers for QTL conditioning vector competence to DENV-2, the protozoan parasite Plasmodium gallinaceum, and the metazoan parasite Brugia malayi. Adapted from [77].

Figure 2

DENV infection and replication cycle in A. aegypti. Compiled from [69,79,83,84].