Genomic homology of the domestic ferret with cats and humans.

We used chromosome paints from both the domestic cat and humans to directly establish chromosomal homology between the genome of these species and the domestic ferret. The chromosome painting data indicate that the ferret has a highly conserved karyotype closer to the ancestral carnivore karyotype than that of the cat. The cat chromosome paints revealed 22 homologous autosomal regions in the ferret genome: 16 ferret chromosomes were hybridized by a single cat paint, while 3 ferret chromosomes were hybridized by two cat paints. In situ hybridization combined with banding showed that ferret Chromosome (Chr) 1 = cat A2p/C2, Chr 2 = F2/C1q, and Chr 3 = A2q/D2. Five ferret chromosomes are homologous to single arms of cat chromosomes: ferret 4 = A1q, 5 = B1q, 6 = C1p, 10 = A1p, and 12 = B1p. The human chromosome paints revealed 32 + XY homologous regions in the ferret genome: 9 ferret chromosomes were each hybridized by a single human paint, 7 by two paints, 3 by three paints. The 10 ferret chromosomes hybridized by multiple human paints produced the following associations: ferret 1 = human 19/3/21, 2 = 8q/2q, 3 = 10/7, 5 = 8/4, 8 = 15/14, 9 = 10/12/22, 11 = 20/2, 12 = 8/4, 14 = 12/22/18, 18 = 19/16. We present an index of genomic diversity, Z, based on the relative number of conserved whole chromosome and chromosome segments as a preliminary statistic for rapid comparison between species. The index of diversity between human-ferret (Z = 0. 812) is slightly less than human-cat (Z = 0.843). The homology data presented here allow us to transfer gene mapping data from both cats and humans to the ferret.