An integrated linkage-radiation hybrid map of the canine genome

Purebred dogs are a unique resource for dissecting the molecular basis of s imple and complex genetic diseases and traits. As a result of strong select ion for physical and behavioral characteristics among the 300 established b reeds, modem dogs are characterized by high levels of interbreed variation, complemented by significant intrabreed homogeneity. A high-resolution map of the canine genome is necessary to exploit the mapping power of this unus ual resource. We describe here the integration of an expanded canine radiat ion hybrid map, comprised of 600 markers, with the latest linkage map of 34 1 markers, to generate a map of 724 markers-the: densest map of the canine genome described to date. Through the inclusion of 217 markers on both the linkage and RH maps, the 77 RH groups are reduced to 44 syntenic groups, th us providing comprehensive coverage of most of the canine genome.