On the robertsonian polymorphism found in the Japanese raccoon dog (Nyctereutes procyonoides viverrinus).

Karyotypes of 39 Japanese raccoon dogs (NPV) which appeared in the literature and of 7 previously unreported specimens were examined. Thirty four individuals showed the standard karyotype 2K = 26M + 10A + (M)X + (A)Y + Bs (2n = 38 + Bs), where Bs are supernumerary chromosomes. The remaining 11 individuals had 2K = 25M + 12A + XY + Bs (2n = 39 + Bs) and one was 2K = 23M + 16A + XY + Bs (2n = 41 + Bs). The G- and C-banding analyses of both somatic and germ cells revealed that these karyotypes with odd numbers are heterozygous (M/A) for a single Robertsonian rearrangement of chromosomes 2, 5, 6, 8, or 11, and one is M/A heterozygous for three autosomes: 5, 6, and 11.