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 genome map that is
both dense and accurate. The resulting resource encompasses
4249 markers, and was constructed using the RHDF5000-2 whole
genome radiation hybrid panel. The radiation hybrid (RH) map
features a density of one marker every 900 Kb and contains
1760 bacterial artificial chromosome clones (BACs) localized
to 1423 unique positions, 851 of which have also been mapped
by fluorescence in situ hybridization (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 2 Mb. For 2233 markers,
the orthologous human genes have been established, 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 a necessary resource for
the canine genome mapping community to undertake positional
cloning experiments and provide new insights into the comparative
canine-human genome maps.