The DAPI banded karyotype of the domestic dog (Canis familiaris) generatedusing chromosome-specific paint probes

The domestic dog (Canis familiaris) is widely used as a model in the study of human disease. However, many of the 78 chromosomes comprising the canine karyotype are extremely difficult to identify reliably by classical cytoge netics. This has been a major hindrance to molecular cytogenetic studies of this species. The Animal Health Trust and the Sanger Centre have developed a set of canine whole chromosome-specific fluorescence in situ hybridisati on (FISH) probes (chromosome paints). We have used these chromosome paints to identify unequivocally each chromosome in a metaphase spread. An increas ing number of laboratories are making use of cooled CCD cameras and sophist icated software for FISH mapping. Consequently, there is a major trend towa rds the use of DAPI banding for concurrent chromosome identification during FISH analyses in a range of species. Here we present, for the first time, a complete DAPI banded karyotype of the dog in which each chromosome has be en accurately placed, together with a 460-band DAPI ideogram. These data wi ll facilitate the accurate assignment of FISH- mapped loci to all chromosom es comprising the karyotype and form the basis for an agreed standard of th e dog karyotype.