Asia-wide phylogeography of wild boar (Sus scrofa) based on mitochondrial DNA and Y-chromosome: Revising the migration routes of wild boar in Asia

Abstract

Genetics of pigs has been well studied in Europe and Asia, but most of previous studies of molecular phylogeny of Sus scrofa have been based on sequences of both wild and domestic forms. In this study we analysed genetic traits of Sus scrofa from 13 regions in Asia (including previously undisclosed Eastern Caucasus and Trans-Baikal regions) using purely wild boar samples. Mitochondrial control region and Y-chromosome genes (AMELY & USP9Y) were employed to resolve phylogeographic relationships. We discussed spatiotemporal dynamics of wild boar distribution and compared molecular data to morphological and cytogenetic data on wild boar variability and taxonomy. A total of 51 haplotypes were detected in mtDNA control region and five haplotypes were found in combined sequences of Y-chromosome genes. The phylogeography of Asia-wide wild boars supported a hypothesis of migration from South-East Asia to South Asia, followed by migration to East and West Asia. We present a hypothesis about independent dispersal of wild boars into West Asia from South and North-East Asia. Mitochondrial DNA phylogeny generally fits the morphologically based intraspecies taxonomy. Distribution of chromosomal variants of wild boar presently does not show clear correlation with mtDNA clades.