Phylogenetic relationships between different raccoon dog (Nyctereutes procyonoides) populations based on four nuclear and Y genes

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.