A Genomic Map of the Effects of Linked Selection in Drosophila. Author Eyal Elyashiv, Shmuel Sattath, Tina Hu, Alon Strutsovsky, Graham McVicker, Peter Andolfatto, Graham Coop, Guy Sella Publication Year 2016 Type Journal Article Abstract Natural selection at one site shapes patterns of genetic variation at linked sites. Quantifying the effects of "linked selection" on levels of genetic diversity is key to making reliable inference about demography, building a null model in scans for targets of adaptation, and learning about the dynamics of natural selection. Here, we introduce the first method that jointly infers parameters of distinct modes of linked selection, notably background selection and selective sweeps, from genome-wide diversity data, functional annotations and genetic maps. The central idea is to calculate the probability that a neutral site is polymorphic given local annotations, substitution patterns, and recombination rates. Information is then combined across sites and samples using composite likelihood in order to estimate genome-wide parameters of distinct modes of selection. In addition to parameter estimation, this approach yields a map of the expected neutral diversity levels along the genome. To illustrate the utility of our approach, we apply it to genome-wide resequencing data from 125 lines in Drosophila melanogaster and reliably predict diversity levels at the 1Mb scale. Our results corroborate estimates of a high fraction of beneficial substitutions in proteins and untranslated regions (UTR). They allow us to distinguish between the contribution of sweeps and other modes of selection around amino acid substitutions and to uncover evidence for pervasive sweeps in untranslated regions (UTRs). Our inference further suggests a substantial effect of other modes of linked selection and of adaptation in particular. More generally, we demonstrate that linked selection has had a larger effect in reducing diversity levels and increasing their variance in D. melanogaster than previously appreciated. Keywords Animals, Selection, Genetic, Amino Acid Substitution, Models, Genetic, Drosophila melanogaster, Genetic Variation, Genome, Insect, Evolution, Molecular, Adaptation, Biological, Chromosome Mapping, Untranslated Regions Journal PLoS Genet Volume 12 Issue 8 Pages e1006130 Date Published 2016 Aug ISSN Number 1553-7404 DOI 10.1371/journal.pgen.1006130 Alternate Journal PLoS Genet PMCID PMC4990265 PMID 27536991 PubMedPubMed CentralGoogle ScholarBibTeXEndNote X3 XML