Ricerc@Sapienza

The Anopheles gambiae complex includes the most efficient vectors of human malaria in sub-Saharan Africa, responsible for hundreds of millions of infections and hundreds of thousands of deaths (WHO, 2016). The two most recently diverged species - A. gambiae and A. coluzzii are recently diverged, having split no later than 540,000 years ago in association to human-made environmental changes. The strongest dependence of A. coluzzii from human-made environmental habitats allowed the expansion of the species range to dry and urban areas suboptimal for A. gambiae, changing malaria transmission patterns geographically, seasonally and ecologically in west-central Africa. The Anopheles gambiae 1000 genomes Consortium (Ag1000G) to which the proposer is associated is building a comprehensive catalogue of genetic variation in natural malaria vector populations. The first paper - including analyses on 765 specimens sampled from 14 locations across Africa and sequenced by Illumina high-throughput technology - highlighted an extraordinary nucleotide diversity. Although high-throughput sequencing technology implemented by the Ag1000G project will continue to produce big amount of data for fine scale genomic studies on A. gambiae and A. coluzzii, these big data will be of limited usage to study the population genetics and ecology, behaviour and vectorial role of these major malaria vectors at a fine geographic scale, which requires genotyping of several thousands of individuals per site. We aim to build on results of the Ag1000G project and to develop and validate novel easy-to-use tools to overcome the limitation of the current approaches in identifying signatures of introgression within A. gambiae and A. coluzzii genomes, and to apply them to shed light on two case studies of adaptive introgression on a trajectory towards hybrid speciation, thus providing novel details on ecological speciation of these organisms at the forefront of research on novel species formation.