Uncovering blowfly feeding habits evolution with functional genetics

Abstract

Blowflies (Diptera: Calliphoridae) are a diverse group of dipterans whose larvaecommonly feed on protein-rich substrates, relying mainly on animal tissues. Such tissuesmay either be from a living or dead host depending on the fly species (which definesthem as parasites or necro-saprophagous, respectively). Some may even choose eitheroption, successfully developing on both substrates (these are called facultativeparasites). It is commonly assumed that parasitism (either facultative, or obligate) is a derivedbehavior that has independently emerged more than once within Calliphoridaetherefore constituting an example of convergent evolution. In my Master's project, Icompare transcriptomic and genomic information of a set of species looking forconvergent molecular patterns (e.g., expression profile or rate of evolution of codingsequences) that correlate with the observed behavioral convergence, especiallyfocusing on the obligate parasites Cochliomyia hominivorax and Chrysomya bezziana.Based on findings made by my laboratory colleagues and some of the work I have done,I have selected three candidate genes (pgant5, Mvl, and Npf) to be tested withfunctional genetics. To do so, I intend to visit Dr. Maxwell J. Scott's laboratory in NorthCarolina State University (Raleigh, NC, United States) for six months where I will betrained in CRISPR/Cas-9 genome editing to try to develop a knock-out stocks of Luciliacuprina, a facultative parasite, for my candidate genes. Once the mutant strains areestablished, I intend to perform behavioral and survival/development assays with thelarvae to assess their food preference and their ability to develop on different media toverify whether they display any shifts compared to wild-type individuals.