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Genetic differentiation of the two subspecies of the smooth newt inhabiting Romania, Triturus vulgaris vulgaris and T. v. ampelensis (Urodela, Salamandridae) as revealed by enzyme electrophoresis

Abstract:

Starch gel electrophoresis was applied to quantify genetic variation and divergence in samples from Romanian populations of the nominal form of the smooth newt Triturus vulgaris and those of the endemic Romanian subspecies T. v. ampelensis, a population from a parapatric area was additionally included. All the samples had similar levels of genetic variation measured by the mean heterozygosity, proportion of polymorphic loci, and mean number of alleles per locus. T. v. ampelensis samples were genetically clearly different from the nominal form samples, the mean genetic distance between the two subspecies was being estimated as DN = 0.114. No fixed differences in allele composition between the two subspecies were found, although some of the alleles were found either exclusively in the nominal form (Aat-1 a) or in T. v. ampelensis (Mpi a). Other alleles at these loci together with Mdh-1 differed markedly in frequency. The population from the parapatric area was intermediate in allelic composition, but grouped together with the T. v. ampelensis samples in a maximum likelihood tree (99.7% bootstrap support for this grouping). The data indicate that the two subspecies interbreed in a parapatric zone. The molecular clock applied to electrophoretic data indicates that these two forms split during the Pleistocene.