Background: The raccoon dog (Nyctereutes procyonoides), endemic to East Asia, is classified as six subspecies according to their geographical distribution including a population introduced to Europe. Studies on phylogenetic relationship or population genetics in both native and introduced areas have been carried out recently. Lately, opinions that Japanese raccoon dogs should be classified as a different species were asserted based on several studies using karyotypes, morphometric characters, mtDNA, and microsatellites analysis. However, no data pertaining to the nuclear DNA (nDNA) or Y chromosome are available.
Objective: To estimate the relationship among the species using different genes is necessary in understanding of the history of this species.
Method: Therefore, we investigated nDNA and Y chromosomes in our study to define relationships: (1) between continental raccoon dog populations, (2) between original and introduced groups, and (3) between continental and Japanese groups.
Results: The analysis of four nuclear (CHRNA1, VTN, TRSP, WT1) and ZFY genes indicated that there had been no genetic differentiation among the continental populations. However, significant differences were observed between continental and Japanese raccoon dogs in VTN and ZFY genes implying genetic differentiation has been going between them.
Conclusion: To better understand the phylogenetic relationship among raccoon dog populations, further study will be necessary.
Keywords: Evolutionary history; Molecular phylogeny; Nuclear DNA; Raccoon dog; Y chromosome.