Effects of structural connectivity on fine scale population genetic structure of muskrat, Ondatra zibethicus

Abstract

In heterogeneous landscapes, physical barriers and loss of structural connectivity have been shown to reduce gene flow and therefore lead to population structuring. In this study, we assessed the influence of landscape features on population genetic structure and gene flow of a semiaquatic species, the muskrat. A total of 97 muskrats were sampled from three watersheds near Sudbury, Ontario, Canada. We estimated population genetic structure using 11 microsatellite loci and identified a single genetic cluster and no genetic differences were found among the watersheds as a result of high levels of gene flow. At finer scales, we assessed the correlation between individual pairwise genetic distances and Euclidean distance as well as different models of least cost path (LCP). We used a range of cost values for the landscape types in order to build our LCP models. We found a positive relationship between genetic distance and least cost distance when we considered roads as corridors for movements. Open landscapes and urban areas seemed to restrict but not prevent gene flow within the study area. Our study underlines the high-dispersal ability of generalist species in their use of landscape and highlights how landscape features often considered barriers to animal movements are corridors for other species.

Digital fragment analysis of short tandem repeats by high‐throughput amplicon sequencing

“…One locus (Oz30b) was removed from the analysis due to an indecipherable repeat pattern likely the result of chimeric PCR amplicons. This locus was commonly removed from analysis in two previous studies by the original developers (Laurence et al 2011(Laurence et al , 2013. In general, the length of alleles by amplicon sequencing was comparable to length of alleles as determined by capillary electrophoresis (Fig.…”

“…This locus was commonly removed from analysis in two previous studies by the original developers (Laurence et al. , ). In general, the length of alleles by amplicon sequencing was comparable to length of alleles as determined by capillary electrophoresis (Fig.…”

Peer Review #2 of "Historical connections among river basins and climatic changes explain the biogeographic history of a water rat (v0.1)"

“…These results indicate that the dependency on rivers could favour the displacement of semiaquatic mammals and, as a consequence, gene flow, resulting in low divergence and shallow genetic structure. For instance, muskrats have an opportunistic behavior in the use of terrestrial landscape and population structure was not influenced by watershed network or landscape composition, and landscape features had a limited effect on gene flow (Laurence, Smith & Schulte-Hostedde, 2013). Some specialist species may be considered generalist in their use of the landscape for dispersal, such as the southern water vole (Centeno-Cuadros, Delibes & Godoy, 2011), which uses several landscape types during dispersal, increasing gene flow.…”

Comparative analysis of landscape effects on spatial genetic structure of the big brown bat and one of its cimicid ectoparasites

“…While our sample sizes for C. adjunctus are relatively small, we used an individual-based analysis, which has been shown to allow for robust landscape genetic inference given small sample sizes (Prunier et al, 2013). Several other studies have used an individual-based approach with sample sizes similar to ours in drawing population genetic and landscape genetic inferences (Broquet et al, 2006;Laurence, Smith, & Schulte-Hostedde, 2013).…”