Genetic differentiation over a small spatial scale in the smooth newt (Lissotriton vulgaris)

Understanding the distribution of genetic variation is central for both population biology and conservation genetics. Genetic population structure can be primarily affected by the species’ dispersal ability, which is assumed to be limited in many amphibians. In this study, we estimated allelic differentiation metrics and FST indices to investigate genetic variation among natural breeding ponds of smooth newts (Lissotriton vulgaris) over a small spatial scale. Based on six microsatellite loci, we found a small, but significant allelic differentiation among clusters of natural breeding ponds (i.e. ‘local regions’), which result was in line with the calculation of corresponding hierarchical FST values. Analysis of molecular variance also indicated significant between-region variation in the study area. Pairwise estimations showed that only the furthermost regions differed from each other in both differentiation measures, but this difference was not attributable to geographic distances between ponds. Our results provide evidence that hierarchical genetic structure can be characteristic to breeding ponds of smooth newts on a small spatial scale in their natural breeding habitat, but dispersal distance may be less limited than previously thought in these philopatric caudates.