Polymorphic microsatellite markers for the muskrat (Ondatra zibethicus)

Abstract

Introduction. The muskrat (Ondatra zibethicus) is a widespread semi-aquatic rodent in North America. In 1954 these mammals were released into several rivers in Lithuania. Methods. The microsatellite markers were used only for the Canadian muskrat populations (Laurence et al., 2009). Consequently, 12 microsatellite primers (Oz06, Oz08, Oz16, Oz17, Oz22, Oz27, Oz30, Oz32, Oz34, Oz41, Oz43, Oz44) were used in this study for the aim to comparing the genetic differentiation between native (Canada) and introduced (Lithuania) populations of muskrats. But only 7 of these 12 microsatellite loci were used in subsequent analyses in case 5 of them (Oz06, Oz16, Oz27, Oz32, Oz34) were not informative or showed inconsistent peak morphology. Results. Population analysis showed high levels of genetic diversity (in Lithuania: He = 0.47– 0.91, Ho = 0.13–1.00; in Canada: He = 0.68–0.96, Ho = 0.48–0.89). The numbers of polymorphic loci were 100% and size ranged from 196 to 276 base pairs in Lithuania and 174 to 278 in Canada. The numbers of alleles per locus ranging from 2 to 14 in the introduced populations of muskrat; in native populations – from 8 to 22, respectively. Each locus was tested for departure from Hardy-Weinberg equilibrium (HWE) and 2 loci exhibited significant in native populations and all loci in introduced populations (Table). Analysis of Molecular Variance (AMOVA) showed that the genetic differences within populations (80% of the total genetic diversity) and among populations (20% of the total genetic diversity) were significant in Lithuania. The results of principal coordinate analysis (PCA) by genetic similarity showed that the population of muskrat in the western parts of Lithuania was furthermost from the population of the middle part of Lithuania. The middle and eastern parts of muskrat populations are the most related by genetically; [...]