Location: Arthropod-Borne Animal Diseases Research
Title: Molecular entomology: analyzing tiny molecules to answer big questions about disease vectors and their biology Authors
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: June 9, 2012
Publication Date: N/A
Technical Abstract: The entomologists at the Arthropod-Borne Animal Diseases Research Unit at USDA-Agricultural Research Service are tasked with protecting the nation’s livestock from domestic, foreign and emerging vector-borne diseases. To accomplish this task, a vast array of molecular techniques are being used in projects including determining the distribution and population dynamics of important vectors as well as examining the biological interactions of vectors with pathogens. We currently are assessing the population structure of the mosquito species Culex tarsalis and Aedes vexans using using RAD-Tag next-gen sequencing. This is a massive population genetics analysis of specimens from 175 collection sites throughout North America. The sequence data will be used to a) identify the mosquitoes’ origin and subsequent geographic spread, b) determine the number and distribution of distinct genetic populations, c) identify the geographic features that are preventing/limiting migration, and d) inform mathematical modeling of outbreaks and mitigation strategies. Other studies at ABADRU use molecular techniques to understand the basic biology of the Dipteran midgut, as well as the intricate interactions between vectors and pathogens. For example, we are using a transcriptomics approach to globally assess genes involved in Dipteran-microbe interactions, including insect innate immune responses, and basic biology of physiological processes such as midgut digestion. Subsequent studies employing tissue-, temporal- or pathogen- specific analysis of gene expression are used to determine the functional role of genes identified from transcriptomes. For example, we have examined the concurrent temporal and spatial expression of antimicrobial genes in the gut of flies in relation to microbe presence, and have revealed key events that determine microbial fate and vector potential. Ongoing studies are aimed at understanding temporal events in blood or sugar meal digestion and vector-pathogen interactions in the important midge vector of arboviruses, Culicoides sonorensis. Knowledge gleaned from these studies has widespread applications including: a) informing risk models (in conjunction with population genetics studies), b) understanding the impact of vector-microbe interactions on the epidemiology of vector borne disease and c) elucidating molecular targets for control strategies and methods.