Phylogeography of the European roe deer Capreolus capreolus as revealed by sequence analysis of the mitochondrial Control Region

Abstract

To assess levels of genetic variation as well as the genetic differentiation among populations, 40 roe deer Capreolus capreolus (Linnaeus, 1758) from 8 European populations were analysed with regard to DNA sequence variation at the highly polymorphic part I of the mitochondrial Control Region. DNA was extracted from liver samples, a 480bp sequence was amplified via PCR and subsequenctly sequenced, yielding 427bp scorable DNA sequence. A total of 22 polymorphic sites were found, defining 19 mitochondrial haplotypes. Levels of overall genetic variation were high with regard to haplotype diversity (δ =0.94) and moderate with regard to nucleotide diversity (π = 0.97%), as compared to other mammalian species. This is indicative of a large present effective population size (Ne) and a former population bottleneck, presumably during the last Pleistocene glaciation. The Norwegian roe deer population appeared to be monomorphic, presumably as an effect of the very recent colonization of Norway by roe deer. Among the central European populations studied, there is a significant correlation between net nucleotide diversity and geographic distance among populations. On the contrary, Nei distances derived from allozyme data of a previous investigation on the same specimens did not show any correlation with geographic distance. It is assumed, that maternal gene flow is restricted due to female philopatry, while nuclear gene flow is pronounced due to male dispersal. A phylogenetic analysis of mitochondrial haplotype relationships revealed two groups of haplotypes with an uneven geographic distribution. One possible explanation is the existence of two separate Pleistocene refugia, where different mitochondrial lineages might have survived. Another possible scenario is one single refugium in Western Europe with a subsequent postglacial recolonization of the continent from West to East. Patterns of nucleotide diversity (π) and the assumed phylogeny of Eastern European mitochondrial haplotypes provide some evidence for the latter hypothesis. However, a more thorough analysis is needed both to accurately estimate levels of genetic variation and to settle the presumable phylogeography of roe deer in Europe.