Post-glacial colonization of eastern Europe from the Carpathian refugium: evidence from mitochondrial DNA of the common voleMicrotus arvalis

Abstract

There is now considerable evidence for the survival of temperate species within glacial refugia that were situated at relatively high latitudes, notably the Carpathian Basin and Dordogne region in Europe. However, the prevalence of fossil remains in such locations is rarely matched by molecular evidence for their contribution to subsequent geographical and demographic expansion of the species in question. One obstacle to this has been insufficient analysis of modern samples from the relevant areas, in particular the parts of eastern Europe that surround the Carpathian refugium. In the present study, we examine the patterns of variation in mitochondrial DNA of the common vole (Microtus arvalis), obtained from existing museum specimens and from newly-collected samples obtained in this area. We show that common voles from one of six extant mitochondrial DNA lineages have colonized most of the species' range in eastern Europe. We contend that the post-glacial dispersal of this lineage most likely originated from the Carpathian refugium, adding support to the argument that such northern refugia made an important contribution to existing genetic diversity in Europe.

Contrasting and congruent patterns of genetic structuring in two Microtus vole species using museum specimens

“…In Eastern Europe, post-LGM expansion has led to the formation of a phylogeographic 'suture zone' in present-day Poland in various mammalian species between multiple mitochondrial DNA (mtDNA) lineages originating from different refugia (Wójcik et al 2010;McDevitt et al 2012). In this region, three mtDNA lineages in the bank vole (Clethrionomys glareolus; Wójcik et al 2010), four lineages in the weasel (Mustela nivalis; McDevitt et al 2012), two lineages in the field vole (Microtus agrestis; Herman et al 2014) and two lineages in the common vole (Microtus arvalis; Stojak et al 2015) are present.…”

“…If we consider the two aforementioned Microtus vole species (the common and field vole), they are morphologically similar species but differ in their population histories in Europe (Herman et al 2014;Stojak et al 2015). For the common vole, two different chromosomal forms have been identified using cytogenetics, arvalis and obscurus.…”

“…The hybrid zone between them occurs in central European Russia (Meyer et al 1997;Haynes et al 2003;Jaarola et al 2004;Bulatova et al 2010aBulatova et al , b, 2013. For the arvalis form, six main mtDNA lineages have been described in Europe: Western-South, Western-North, Central, Italian, Eastern and Balkan (Haynes et al 2003;Tougard et al 2008;Bužan et al 2010;Martínková et al 2013;Stojak et al 2015). For the field vole, three main evolutionary units (which may represent cryptic species) have been described-Portuguese, Southern and Northern (Paupério et al 2012).…”

“…For the Northern evolutionary unit in the field vole, six main mtDNA lineages have been identified: Eastern, Scandinavian, Central European, French, North British and Western (Herman and Searle 2011;Herman et al 2014). The differences in the distribution and origin of the mtDNA lineages between the common and field vole are evident in Poland (Herman et al 2014;Stojak et al 2015). The phylogeographic suture zone in Poland that was formed after the LGM in the common vole consists of two lineages, the Eastern lineage likely originating from the Carpathian refugium (based on fossil records and molecular data ;Pazonyi 2004;Sommer and Nadachowski 2006;Stojak et al 2015) and the Central lineage from a refugium originally suggested to be Italy (Haynes et al 2003) but likely located further north (Heckel et al 2005; based on molecular data).…”

“…It is therefore apparent that different historical and contemporary processes may impact upon patterns of genetic structure in these two Microtus species. Several studies have now described the phylogeography and genetic structure of multiple mammalian species using mtDNA in the vicinity of present-day Poland (Wójcik et al 2010;McDevitt et al 2012;Stojak et al 2015). However, there has been little attempt to study the influence of these ancient processes on contemporary genetic structure in this region.…”