Population structure, colonization processes and barriers for dispersal in Polish common hamsters (Cricetus cricetus)

Abstract

The phylogeographic relationships of common hamster (Cricetus cricetus) populations in Poland were determined by the analysis of three partial mtDNA sequences: control region, cytochrome b and 16S rRNA. A phylogenetic tree as well as parsimony network, consistently separate Polish common hamsters into two groups: E1 being so far specific for the area of Poland, and P3 which clusters inside a Pannonian lineage, previously described from the Carpathian Basin. Polish hamsters do not share any haplotypes with the ÔNorthÕ -lineage from Germany and Western Europe, although Poland most likely represents the main migration corridor from the eastern distribution centre to the western boundary of the species range. Fossil and DNA data indicate a very recent appearance of the E1 lineage in the Polish Uplands, probably at the very end of the last glaciation. On the other hand, the Pannonian group entered southern Poland as early as the second stadial of the last glaciation (Middle Vistulian 53.35 ka). The hamster lineages in Poland seem to show different population structures and demographic histories.

The genetic characterization of an isolated remnant population of an endangered rodent (Cricetus cricetus L.) using comparative data: implications for conservation

“…between the Pannonia and West lineages (Smulders et al 2003) or between the Pannonia and Central lineages (Neumann et al , 2005, and results of this study); (2) reports exist showing that the contemporary hamsters have reduced fitness relative to those alive prior to the population crisis (e.g. Pucek 1981; Monecke et al 2013), thus the beneficial effect of proposed outcrossing, such as heterosis, may be observed, and (3) biological importance of postulated ESUs is not always clearly defined and understood, and subspecies designation is not broadly accepted Banaszek et al 2009Banaszek et al -2010Schröder et al 2014). In conclusion, if the decline in genetic diversity is strictly due to neutral processes in JW, introducing a new genetic variant would be beneficial.…”

“…Any plans of translocation should not include transfer of individuals representing different evolutionarily significant units (ESU) to avoid diminishing differently adapted variants and to prevent potentially detrimental consequences of outbreeding depression (e.g. La Haye et al 2012, see also;Banaszek et al 2009Banaszek et al -2010Neumann 2013;Schröder et al 2014). Taking into account this position, translocation should be between JW and the Central population(s).…”

“…This latter lineage is also present in the neighboring Ukraine from where it probably originates (Neumann et al 2005;Banaszek et al 2010). The P3 populations inhabited Polish areas from source populations in Moravia and Slovakia using the natural route through the Moravian Gate valley between the Sudetes and the western Carpathian Mountains in the Czech Republic (Ziomek and Banaszek 2007;Banaszek et al 2009Banaszek et al , 2010.…”

“…At the end of the Würm glaciation, and in an interglacial that began 10,000-12,000 years ago, the range expanded again to encompass central and western Europe. At that time Poland became inhabited by new haplotypes derived from eastern refugia as well as from the Carpathian Basin (Banaszek et al 2010;Korbut and Banaszek 2016).…”

“…However, many aspects of the phylogenetic relationships are still unresolved, concerning for example the branching pattern in the eastern part of the species range. One group, denoted as E, spans several lineages with a western distribution border in central Europe; a Pannonia group is restricted to the Carpathian Basin and the southern part of Poland (Banaszek et al 2010).…”