title: The extent and distribution of linkage disequilibrium in a multi-hierarchic outbred canine pedigree.
abstract: A canine integrated linkage-radiation map has been recently constructed by using microsatellite markers. This map, with a good coverage of the canine genome, allows for a genome-wide search for the extent and distribution of linkage disequilibrium derived from linkage and evolutionary forces. In this study, we genotyped an outbred pedigree between Labrador retriever and Greyhound breeds with a set of microsatellite markers (240) from the canine linkage map. Linkage disequilibrium was measured between all syntenic and nonsyntenic marker pairs. Analysis of syntenic pairs revealed a significant correlation (-0.229, P < 0.001) between linkage disequilibrium and genetic distance (log transformed). Significant linkage disequilibria were observed more frequently between syntenic pairs spaced <40 cM than those paced >40 cM. There is a clear trend for linkage disequilibrium to decline with marker distance. From our results, a genome-wide screen with markers at low to moderate density (1-2 per 10 cM) should take full advantage of linkage disequilibrium for quantitative trait locus mapping in dogs. This study supports the appropriateness of linkage disequilibrium analysis to detect and map quantitative trait loci underlying complex traits in dogs.
authors.affiliation: Department of Statistics, 533 McCarty Hall C, University of Florida, Gainesville, Florida 32611, USA.
authors.forename: Xiang-Yang
authors.initials: XY
authors.lastname: Lou
authors.forename: Rory J
authors.initials: RJ
authors.lastname: Todhunter
authors.forename: Min
authors.initials: M
authors.lastname: Lin
authors.forename: Qing
authors.initials: Q
authors.lastname: Lu
authors.forename: Tian
authors.initials: T
authors.lastname: Liu
authors.forename: Zuoheng
authors.initials: Z
authors.lastname: Wang
authors.forename: Stuart P
authors.initials: SP
authors.lastname: Bliss
authors.forename: George
authors.initials: G
authors.lastname: Casella
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Acland
authors.forename: George
authors.initials: G
authors.lastname: Lust
authors.forename: Rongling
authors.initials: R
authors.lastname: Wu
mesh_terms: D000818:Animals; D001947:Breeding; D002874:Chromosome Mapping; D003433:Crosses, Genetic; D004285:Dogs / Q000235:genetics*; D005787:Gene Frequency; D006579:Heterozygote; D015810:Linkage Disequilibrium / Q000235:genetics*; D018895:Microsatellite Repeats / Q000235:genetics; D008957:Models, Genetic; D010375:Pedigree