ABSTRACT

Background. The 156 breeds of dog recognized by the American Kennel  
Club offer a unique opportunity to map genes important in genetic  
variation. Each breed features a defining constellation of  
morphological and behavioral traits, often generated by deliberate  
crossing of closely related individuals, leading to a high rate of  
genetic disease in many breeds. Understanding the genetic basis of both  
phenotypic variation and disease susceptibility in the dog provides new  
ways in which to dissect the genetics of human health and biology.

Results. To facilitate both genetic mapping and cloning efforts, we  
have constructed an integrated canine map that is both dense and  
accurate. The resulting resource encompasses 4249 markers, and was  
constructed using the RHDF5000-2 panel. The map features a density of  
one marker every 900Kb and contains a total of 1760 mapped bacterial  
artificial chromosome clones (BACs) localized to 1423 unique positions,  
804 of which have also been mapped by fluorescence in situhybridization  
(FISH). The two data sets show excellent concordance. Excluding the Y  
chromosome, the map features an RH/FISH mapped BAC every 3.5 Mb and an  
RH mapped BAC-end, on average, every 2Mb. For over 2200 markers, the  
orthologous human gene  has been identified,allowing the identification  
of 79 conserved segments (CS) between the dog and human genomes,  
dramatically extending the length of most previously described CS.

Conclusions. These results provide necessary resource for the canine  
genome mapping community to undertake positional cloning experiments  
and provide new insights into the comparative canine-human genome maps.