Linkage disequilibrium on the bovine X chromosome: characterization and use in quantitative trait locus mapping

Journal article

We herein demonstrate that in the Holstein–Friesian dairy cattle population, microsatellites are as polymorphic on the X chromosome as on the autosomes but that the level of linkage disequilibrium between these markers is higher on the X chromosome than on the autosomes. The latter observation is not compatible with the small male-to-female ratio that prevails in this population and results in a higher gonosomal than autosomal effective population size. It suggests that the X chromosome undergoes distinct selective or mutational forces. We describe and characterize a novel Markovian approach to exploit this linkage disequilibrium to compute the probability that two chromosomes are identical-by-descent conditional on flanking marker data. We use the ensuing probabilities in a restricted maximum-likelihood approach to search for quantitative trait loci (QTL) affecting 48 traits of importance to the dairy industry and provide evidence for the presence of QTL affecting 5 of these traits on the bovine X chromosome.

Authors: Sandor, C; Farnir, F; Hansoul, S; Coppieters, W; Meuwissen, T

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Genetics Society of America
• Journal: Genetics
• Volume: 173
• Issue: 3
• Pages: 1777-1786
• Publication date: 2006-04-01
• DOI: 10.1534/genetics.106.059329
• ISSN: 0016-6731