Re-examination of the chromosome homology between two subspecies of Japanese raccoon dogs (Nyctereutes procyonoides albus and N.p. viverrinus)

We investigated the chromosomal relationships between subspecies of Japanese raccoon dogs from Hokkaido (Nyctereutes procyonoides albus; NP A) and all of the other major Japanese Islands (N. p. viverrinus; NPV). Chromosomes of wild-caught NPA were analyzed by conventional stain, G-banding and C-banding techniques. The basic karyotype of this subspecies is composed of met acentric (M) and acrocentric (A) chromosomes plus a variable number of B chromosomes (2n = 38 ( = 26M + 10A + XY or XX) + Bs) and is the same as that of NPV. This study of NP A suggests that the Island type (2n = 38) only occurs in Japanese islands including Hokkaido, whereas all animals from mainland Asia and eastern Europe that have been examined have the Continental type (2n = 54).