Evolutionary genetics and mechanisms of plant adaptation and reproductive isolation in aphids – SPECIAPHID

The role of ecological factors and biological adaptations in species formation has gained strong support in the last decade. However, the precise steps involved in the accomplishment of ecological specialization and reproductive isolation are not fully understood and neither is the evolutionary time needed for such an accomplishment. Here, we take advantage of the pea aphid species/biotype complex, which conveniently shows a continuum of genetic divergence from sympatric host races to incipient species, to deeply explore the evolutionary genetics of plant adaptation and ecological speciation using a multidisciplinary approach combining genome evolution and functional studies. This three-year project relies on already acquired data and it will also generate additional resources, including several re-sequenced genomes of pea aphid biotypes, high-density genome scans, transcriptomic data and dedicated specialized databases. This project involves 4 partners interacting with scientists in the UK, organized into a French-British consortium and contributing complementary skills in evolutionary biology, functional genomics and physiology, population genetics and bioinformatics. It is divided in 4 connected scientific tasks (plus a coordination task) aimed at achieving major progress in the understanding of the molecular evolutionary basis of plant adaption and reproductive isolation in the pea aphid complex. We expect gaining insights into the role of plant specialization in insect diversification, and the genomic architecture and factors underlying plant adaptation and reproductive isolation. Furthermore, we will provide a first inventory of candidate genes responsible for plant specialization, setting the stage for more functional studies in a near future.