Differentiation of Alpine marmot populations traced by DNA fingerprinting.

As revealed by allozyme studies, the genetic variation of the Alpine marmot (Marmota m. marmota) has been reduced by a species-wide bottleneck at the end of the last glaciation. Therefore the more variable microsatellite loci were used as a genetic marker system to investigate variablility and differentiation of four autochthonous and four allochthonous populations founded by the release of small numbers of individuals during the last 150 years. The microsatellite loci detected by the DNA-probe (ATCC)₄ were found to be polymorphic in all populations, but the amount of variation was lower than in comparable mammalian species. In spite of founder effects the variation in the allochthonous populations was not significanlty reduced compared to the autochthonous populations. The autochthonous populations from Austria and from the eastern part of Switzerland were genetically similar, only the population from western Switzerland was clearly differentiated from the others. In the allochthonous populations similarities in the microsatellite patterns reveal genetic affinities to putative autochthonous source populations of the founder individuals.