Highly Parallel Genomic Selection Response in Replicated Drosophila melanogaster Populations with Reduced Genetic Variation. (25th October 2021)

• Record Type: Journal Article
• Authors: Burny, Claire; Nolte, Viola; Dolezal, Marlies; Schlötterer, Christian
• Editors: Baer, Charles
• Is Part Of: Genome biology and evolution. Volume 13:Number 11(2021)
• Publication Date: 2021-10-25
• Subjects: experimental evolution -- evolve and resequence -- inbred strains -- polygenic trait -- parallelism -- Drosophila melanogaster; Genomics -- Periodicals; Genes -- Periodicals; 572.8605
• DOI: 10.1093/gbe/evab239
• Languages: English
• ISSNs: 1759-6653

Abstract

Abstract: Many adaptive traits are polygenic and frequently more loci contributing to the phenotype are segregating than needed to express the phenotypic optimum. Experimental evolution with replicated populations adapting to a new controlled environment provides a powerful approach to study polygenic adaptation. Because genetic redundancy often results in nonparallel selection responses among replicates, we propose a modified evolve and resequence (E&R) design that maximizes the similarity among replicates. Rather than starting from many founders, we only use two inbred Drosophila melanogaster strains and expose them to a very extreme, hot temperature environment (29 °C). After 20 generations, we detect many genomic regions with a strong, highly parallel selection response in 10 evolved replicates. The X chromosome has a more pronounced selection response than the autosomes, which may be attributed to dominance effects. Furthermore, we find that the median selection coefficient for all chromosomes is higher in our two-genotype experiment than in classic E&R studies. Because two random genomes harbor sufficient variation for adaptive responses, we propose that this approach is particularly well-suited for the analysis of polygenic adaptation.