Our current and future research plans are directed towards elucidating the molecular basis of inherited diseases in companion animals. We are interested in developing tests to help breeders eliminate inherited diseases in dogs and horses. A large number of the diseases seen in veterinary practice that affect purebred animals have a heritable basis. Characterizing inherited disease in dogs has the added benefit of providing an animal model for human diseases. Presently we have projects in both horses and dogs. We are investigating the mode of inheritance of a skin disease seen in the American Quarter Horse. We are also currently working to characterize the molecular nature of urinary calculi formation in Dalmatians. In addition to determining the molecular nature of inherited diseases in animals, we are also working on a project to understand the relationship between different dog breeds. We are developing polymorphic markers for the canine Y chromosome. One would expect that dogs would show breed-specific alleles of genes that code for traits that define the breed like coat color, hunting ability, and size. Additionally, markers in the non-recombining region of the Y chromosome might be representative of the founding male dogs for that breed. To evaluate the male founder effect we have begun to identify microsatellite markers and single nucleotide polymorphisms from the Y chromosome. We will use these markers to evaluate Y chromosome haplotypes for different dog breeds. Not only will this study determine the heterogeneity of the male line in the breeds evaluated but, it may also be a method to determine the inter-relationship of the different breeds and could indeed provide breed specific markers. Breed-specific markers would be useful for parentage testing, forensics and the maintenance of breed registries. E-mail dlbannasch@ucdavis.edu for more information.