Chromosome-specific single-locus FISH probes allow anchorage of an 1800-marker integrated radiation-hybrid/linkage map of the domestic dog genome to all chromosomes

We present here the first fully integrated, comprehensive map of the canine genome, incorporating detailed cytogenetic, radiation hybrid (RH), and mei otic information. We have mapped a collection of 266 chromosome-specific co smid clones, each containing a microsatellite marker, to all 38 canine auto somes by fluorescence in situ hybridization (FISH). A 1500-marker RH map, c omprising 1078 microsatellites, 320 dog gene markers, and 102 chromosome-sp ecific markers, has been constructed using the RHDF5000-2 whole-genome radi ation hybrid panel. Meiotic linkage analysis was performed, with at least o ne microsatellite marker from each dog autosome on a panel of reference fam ilies, allowing one meiotic linkage group to be anchored to all 38 dog auto somes. We present a karyotype in which each chromosome is identified by one meiotic linkage group and one or more RH groups. This updated integrated m ap, containing a total of 1800 markers, covers > 90% of the dog genome. Pos itional selection of anchor clones enabled us, for the first time, to orien tate nearly all of the integrated groups on each chromosome and to evaluate the extent of individual chromosome coverage in the integrated genome map. Finally, the inclusion of 320 dog genes into this integrated map enhances existing comparative mapping data between human and dog, and the 1000 mappe d microsatellite markers constitute an invaluable tool with which to perfor m genome scanning studies on pedigrees of interest.