AN INTEGRATED GENETIC AND PHYSICAL MAP OF THE BOVINE X-CHROMOSOME

Genotypic data for 56 microsatellites (ms) generated from maternal ful l sib families nested within paternal half sib pedigrees were used to construct a linkage map of the bovine X Chromosome (Chr) (BTX) that sp ans 150 cM (ave. interval 2.7 chi). The linkage map contains 36 previo usly unlinked ms; seven generated from a BTXp library. Genotypic data from these 36 ms was merged into an existing linkage map to more than double the number of informative BTX markers. A male specific linkage map of the pseudoautosomal region was also constructed from five ms at the distal end of BTXq. Four informative probes physically assigned b y fluorescence in situ hybridization defined the extent of coverage, c onfirmed the position of the pseudoautosomal region on the q-arm, and identified a 4.1-cM marker interval containing the centromere of BTX.