Reconstructing the colonization history of lost wolf lineages by the analysis of the mitochondrial genome

Abstract

The grey wolves (Canis lupus) originally inhabited major parts of the Northern hemisphere, but many local populations became extinct. Two lineages of wolves in Japan, namely, Japanese or Honshu (C. l. hodophilax) and Ezo or Hokkaido (C. l. hattai) wolves, rapidly went extinct between 100 and 120years ago. Here we analyse the complete mitochondrial genome sequences from ancient specimens and reconstruct the colonization history of the two extinct subspecies. We show a unique status of Japanese wolves in wolf phylogeny, suggesting their long time separation from other grey wolf populations. Japanese wolves appeared to have colonized the Japanese archipelago in the Late Pleistocene (ca. 25,000-125,000years ago). By contrast, Ezo wolves, which are clearly separated from Japanese wolves in phylogeny, are likely to have arrived at Japan relatively recently (<14,000years ago). Interestingly, their colonization history to Japan tallies well with the dynamics of wolf populations in Europe and America during the last several millennia. Our analyses suggest that at least several thousands of wolves once inhabited in the Japanese archipelago. Our analyses also show that an enigmatic clade of domestic dogs is likely to have originated from rare admixture events between male dogs and female Japanese wolves.

Keywords: Canis lupus; Colonization; Domestic dog; Ezo wolf; Japanese wolf; Molecular phylogeny.