Mecadapt

Adaptation of organisms to contrasting environmental conditions is a major driver of species diversification. However we know very little on the genetic basis underlying ecologically-relevant traits, and on how and at what speed adaptive divergence leads to genetic differentiation. Here, we will use the pea aphid, a well-suited system for adaptive genomics, which conveniently shows a complex of plant-specialized biotypes, ranging from sympatric host races to incipient species, and resulting from a recent adaptive radiation. By combining novel phylogenetic and population genetic analyses of massive genomic dataset, innovative tools for functional analysis and unique biological resources, we will 1) reconstruct the evolutionary history of plant specialization and biotype formation, 2) identify genomic regions under divergent selection and characterize the genomic architecture underlying plant-based differentiation, and 3) identify genes and functions involved in plant specialization in the pea aphid complex. This project relies on a consortium of 3 French partners and 2 associate partners from other European countries who will bring complementary skills and know-how for the development of multidisciplinary approaches and combination of methods needed to reach project's objectives. This project will allow testing whether multiple independent events of adaptation to different environments involve the same genomic regions and the same set of genes and how genetic divergence accumulates along the genome through time in reproductive isolation. It will also increase knowledge on how insects overcome plant defenses and acquire new hosts on which they may become adapted, paving the way for the development of sustainable control strategies against aphids as important crop pests, based on enhanced plant defenses.