Maternal genomic variability of the wild boar (Sus scrofa) reveals the uniqueness of East‐Caucasian and Central Italian populations

Abstract

The phylogeography of the European wild boar was mainly determined by postglacial recolonization patterns from Mediterranean refugia after the last ice age. Here we present the first analysis of SNP polymorphism within the complete mtDNA genome of West Russian (n = 8), European (n = 64), and North African (n = 5) wild boar. Our analyses provided evidence of unique lineages in the East‐Caucasian (Dagestan) region and in Central Italy. A phylogenetic analysis revealed that these lineages are basal to the other European mtDNA sequences. We also show close connection between the Western Siberian and Eastern European populations. Also, the North African samples were clustered with the Iberian population. Phylogenetic trees and migration modeling revealed a high proximity of Dagestan sequences to those of Central Italy and suggested possible gene flow between Western Asia and Southern Europe which was not directly related to Northern and Central European lineages. Our results support the presence of old maternal lineages in two Southern glacial refugia (i.e., Caucasus and the Italian peninsula), as a legacy of an ancient wave of colonization of Southern Europe from an Eastern origin.

Clear phylogeographic pattern and genetic structure of wild boar Sus scrofa population in Central and Eastern Europe

“…The mtDNA studies and localization of subfossil remains indicated that in Europe the species survived the Last Glacial Maximum (LGM) in southern refugia. The mtDNA lineages of wild boar inhabiting Italy, the Caucasus Mountains and the Near East are distinct from all other lineages occurring in western Eurasia 5 , 26 . Veličković et al 19 showed high frequencies of private microsatellite alleles in the populations inhabiting the three southern peninsulas (Iberian, Italian and Balkan), which confirmed the uniqueness of those populations.…”

“…Almost all of them (except several individuals with Asiatic haplotypes, comp. 26 , 27 ) grouped in one mtDNA lineage called E1, which were further divided into clades E1-A and E1-C. The majority of individuals occurring in Central and Eastern Europe belonged to clade E1-C 27 .…”

“…Until now the results of almost all studies concerning the phylogenetic and phylogeographic studies of wild boar in Europe have been based on analyses of relatively short fragments of mtDNA control region (411 bp in 5 ; 443 bp in 25 ; 637 bp in 24 ; 664 bp in 27 ). A recently published study by Khederzadeh et al 26 for the first time showed the results of phylogenetic analyses of the complete mtDNA genome of wild boar from large areas in North Africa, Europe and Western Asia. The authors evidenced that the Italian E2 lineage of wild boar was closely related to that in the eastern Caucasus Mts., and those lineages were basal to other European haplotypes of the species.…”

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

“…Here we report the same connections for the area situated north from the Caucasian mountain ridge. Khederzadeh et al [43] suggested the possibility of genetic connection of Dagestan wild boars to Italian rather than to Central of East European haplotypes. Our data indicate connection of Eastern Caucasus to NE clade.…”

“…Wu et al [16] suggested possible ways of expansion of pigs and wild boars within East-Asian regions but did not discuss how they could be related to western haplogroups. In the articles focusing on the genetic status of Near Eastern wild boars [20,43] animals from Turkey, Iran and Trans-Caucasian countries were described as belonging to European, Asian or Near Eastern haplogroups, but the history and relationships between these groups have not been discussed. Thus patterns of wild boar expansion in Asia remain unclear [12].…”