Genomic Analysis of European Drosophila melanogaster Populations Reveals Longitudinal Structure, Continent-Wide Selection, and Previously Unknown DNA Viruses

Martin Kapun, Maite G Barrón, Fabian Staubach, Darren J Obbard, R Axel W Wiberg, Jorge Vieira, Clément Goubert, Omar Rota-Stabelli, Maaria Kankare, María Bogaerts-Márquez, Annabelle Haudry, Lena Waidele, Iryna Kozeretska, Elena G Pasyukova, Volker Loeschcke, Marta Pascual, Cristina P Vieira, Svitlana Serga, Catherine Montchamp-Moreau, Jessica Abbott, Patricia Gibert, Damiano Porcelli, Nico Posnien, Alejandro Sánchez-Gracia, Sonja Grath, Élio Sucena, Alan O Bergland, Maria Pilar Garcia Guerreiro, Banu Sebnem Onder, Eliza Argyridou, Lain Guio, Mads Fristrup Schou, Bart Deplancke, Cristina Vieira, Michael G Ritchie, Bas J Zwaan, Eran Tauber, Dorcas J Orengo, Eva Puerma, Montserrat Aguadé, Paul Schmidt, John Parsch, Andrea J Betancourt, Thomas Flatt, Josefa González


Genetic variation is the fuel of evolution, with standing genetic variation especially important for short-term evolution and local adaptation. To date, studies of spatiotemporal patterns of genetic variation in natural populations have been challenging, as comprehensive sampling is logistically difficult, and sequencing of entire populations costly. Here, we address these issues using a collaborative approach, sequencing 48 pooled population samples from 32 locations, and perform the first continent-wide genomic analysis of genetic variation in European Drosophila melanogaster. Our analyses uncover longitudinal population structure, provide evidence for continent-wide selective sweeps, identify candidate genes for local climate adaptation, and document clines in chromosomal inversion and transposable element frequencies. We also characterize variation among populations in the composition of the fly microbiome, and identify five new DNA viruses in our samples.