Phylogeography and population structure of the wild boar Sus scrofa in northeast Asia based on mitochondrial DNA control region variation analysis

摘要

The wild boar (Sus scrofa), which inhabits wide areas of Asia, Europe, and North Africa, is an ancestral species of domestic pigs with 27 subspecies. Five subspecies inhabiting Northeast Asia are the Ussurian wild boar (S. s. ussuricus), the North China wild boar (S. s. moupinensis), the Japanese wild boar (S. s. leucomystax), the Ryukyu wild boar (S. s. riukiuanus), and the Korean wild boar (S. s. coreanus). Total of 144 mitochondrial DNA (mtDNA) control regions of wild boars from these areas were analyzed and the phylogeographic characteristics and genetic population structure were investigated. Thirty-four wild boar haplotypes detected from the whole sequences of the mtDNA control region were analyzed using the neighbor-joining method. The phylogenetic relationship indicates that the wild boars in Northeast Asia share a common ancestor. The Japanese wild boars were more closely related to Northeast China wild boars than the others, and the Ryukyu wild boars have a closer relationship with the Northern China wild boars. Nested contingency analysis of geographical associations and the nested cladistic analysis of geographical distance for the mtDNA haplotypes of control region indicate that there is significant geographical population structure in wild boars of Northeast Asia. The results also suggest that: (1) the ancestral population had experienced a long distance movement to establish the contemporary population；(2) the Ryukyu wild boar population may descend from the continental boar, and it may have experienced allopatric fragmentation in the past；(3) the Northern China wild boar population in southern areas has higher genetic diversity than that in the northern areas, and the population has experienced contiguous range expansions