Evolution of complex traits: the example of feeding habits in Calliphoridae

Abstract

The main objective of this project is to understand the evolution of parasitism in blowflies of the family Calliphoridae, which have a worldwide distribution with representatives classified as livestock pests. Calliphorids have diverse feeding habits, which include necrophagy (decomposing material diet), obligate parasitism (live tissue diet) and facultative parasitism (generalist strategy). We propose to study the evolutionary trajectory of these habits at the genomic, transcriptomic and organismal levels.With genomic and transcriptomic data from eight calliphorids, as well as, from other closely related flies (e.g. the tsetse flies), a global comparison will be carried out, focused on identifying the genes, gene families and gene functions necessary for the different feeding lifestyles (e.g. evolutionary rate, identification of diet-specific genes).In a complementary approach, we will study the biology of a facultative parasite of great sanitary and economical impact: Lucilia cuprina. The larvae of this species can survive feeding either on live tissues (parasitic mode) or on decomposing material (necrophagous mode). By experimentally creating lines of L. cuprina, selected for >10 generations, using either parasitic or necrophagous larval substrate, we propose to identify the genes and polymorphisms necessary for a necrophagous or parasitic lifestyle using bioinformatics (RNA-seq and DNA-seq) and gene editing techniques (CRISPR/Cas9). Moreover, we will document various characteristics of the biology of the species before and after selection (substrate preference, fecundity, viability, development).