title: The use of genetic markers to measure genomic response to selection in livestock.
abstract: A method to measure genomic response to natural and artificial selection by means of genetic markers in livestock is proposed. Genomic response through several levels of selection was measured using sequential testing for distorted segregation of alleles among selected and nonselected sons, single-sperm typing, and a test with records for growth performance. Statistical power at a significance level of 0.05 was >0.5 for a marker linked to a QTL with recombination fractions 0, 0.10, and 0.20 for detecting genomic responses for gene effects of 0.6, 0.7, and 1.0 phenotypic standard deviations, respectively. Genomic response to artificial selection in six commercial bull sire families comprising 285 half-sib sons selected for growth performance was measured using 282 genetic markers evenly distributed over the cattle genome. A genome-wide test using selected sons was significant (P < 0.001), indicating that selection induces changes in the genetic makeup of commercial cattle populations. Markers located in chromosomes 6, 10, and 16 identified regions in those chromosomes that are changing due to artificial selection as revealed by the association of records of performance with alleles at specific markers. Either natural selection or genetic drift may cause the observed genomic response for markers in chromosomes 1, 7, and 17.
authors.affiliation: Centre UdL-IRTA, Area de Produccio Animal, 25198 Lleida, Spain. luis.gomez@irta.es
authors.forename: Luis
authors.initials: L
authors.lastname: Gomez-Raya
authors.forename: Hanne Gro
authors.initials: HG
authors.lastname: Olsen
authors.forename: Frode
authors.initials: F
authors.lastname: Lingaas
authors.forename: Helge
authors.initials: H
authors.lastname: Klungland
authors.forename: Dag Inge
authors.initials: DI
authors.lastname: Våge
authors.forename: Ingrid
authors.initials: I
authors.lastname: Olsaker
authors.forename: Seblewengel Bekele
authors.initials: SB
authors.lastname: Talle
authors.forename: Monica
authors.initials: M
authors.lastname: Aasland
authors.forename: Sigbjørn
authors.initials: S
authors.lastname: Lien
mesh_terms: D000818:Animals; D002417:Cattle / Q000235:genetics*; D005260:Female; D005819:Genetic Markers; D016013:Likelihood Functions; D015810:Linkage Disequilibrium; D008297:Male; D040641:Quantitative Trait Loci; D012641:Selection, Genetic; D013094:Spermatozoa / Q000502:physiology
chemical_list: D005819:Genetic Markers