Genome-Wide Effects of Long-Term Divergent Selection

• DOI: 10.1371/journal.pgen.1001188
• Publication Date: 2010-11-04T19:48:06Z
• Authors: Anna M. Johansson; Mats E. Pettersson; Paul B. Siegel; Örjan Carlborg
• Keywords: 2. Zero hunger; Heterozygote; 0303 health sciences; Genome; Time Factors; Body Weight; Genetic Variation; QH426-470; Polymorphism, Single Nucleotide; Chromosomes; 03 medical and health sciences; Quantitative Trait, Heritable; Gene Frequency; Genetic Loci; Genetics; Animals; Computer Simulation; Selection, Genetic; Base Pairing; Chickens; Alleles; Research Article

To understand the genetic mechanisms leading to phenotypic differentiation, it is important to identify genomic regions under selection. We scanned the genome of two chicken lines from a single trait selection experiment, where 50 generations of selection have resulted in a 9-fold difference in body weight. Analyses of nearly 60,000 SNP markers showed that the effects of selection on the genome are dramatic. The lines were fixed for alternative alleles in more than 50 regions as a result of selection. Another 10 regions displayed strong evidence for ongoing differentiation during the last 10 generations. Many more regions across the genome showed large differences in allele frequency between the lines, indicating that the phenotypic evolution in the lines in 50 generations is the result of an exploitation of standing genetic variation at 100s of loci across the genome.