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On the North American Great Plains, several snake species reach their northern range limit where they rely on sparsely distributed hibernacula located in major river valleys. Independent colonization histories for the river valleys and barriers to gene flow caused by the lack of suitable habitat between them may have produced genetically differentiated snake populations. To test this hypothesis, we used 10 microsatellite loci to examine the population structure of two species of conservation concern in Canada: the eastern yellow-bellied racer (Coluber constrictor flaviventris) and bullsnake (Pituophis catenifer sayi) in 3 major river valleys in southern Saskatchewan. Fixation indices (FST) showed that populations in river valleys were significantly differentiated for both species (racers, FST = 0.096, P = 0.001; bullsnakes FST = 0.045–0.157, P = 0.001). Bayesian assignment (STRUCTURE) and ordination (DAPC) strongly supported genetically differentiated groups in the geographically distinct river valleys. Finer-scale subdivision of populations within river valleys was not apparent based on our data, but is a topic that should be investigated further. Our findings highlight the importance of major river valleys for snakes at the northern extent of their ranges, and raise the possibility that populations in each river valley may warrant separate management strategies. [ABSTRACT FROM AUTHOR]

Thermal pollution from industrial processes can have negative impacts on the spawning and development of cold-water fish. Point sources of thermal effluent may need to be managed to avoid affecting discrete populations. Correspondingly, we examined fine-scale ecological and genetic population structure of two whitefish species (Coregonus clupeaformis and Prosopium cylindraceum) on Lake Huron, Canada, in the immediate vicinity of thermal effluent from nuclear power generation. Niche metrics using δ13C and δ15N stable isotopes showed high levels of overlap (48.6 to 94.5%) in resource use by adult fish captured in areas affected by thermal effluent compared to nearby reference locations. Isotopic niche size, a metric of resource use diversity, was 1.3- to 2.8-fold higher than reference values in some thermally affected areas, indicative of fish mixing. Microsatellite analyses of genetic population structure (Fst, STRUCTURE and DAPC) indicated that fish captured at all locations in the vicinity of the power plant were part of a larger population extending beyond the study area. In concert, ecological and genetic markers do not support the presence of an evolutionarily significant unit in the vicinity of the power plant. Thus, future research should focus on the potential impacts of thermal emissions on development and recruitment. [ABSTRACT FROM AUTHOR]

• Premise of the study: Microsatellite loci were developed for the epiphytic pencil orchid Dendrobium calamiforme for population genetic and phylogeographic investigation of this Australian taxon. • Methods and Results: Nineteen microsatellite loci were identified from an Illumina paired-end shotgun library of D. calamiforme. Polymorphism and genetic diversity were assessed in 24 individuals from five populations separated by a maximum distance of ∼80 km. All loci were polymorphic with two to 14 alleles per locus, expected heterozygosity ranging from 0.486 to 0.902, and probability of identity values ranging from 0.018 to 0.380. • Conclusions: These novel markers will serve as valuable tools for investigation of levels of genetic diversity as well as patterns of gene flow, genetic structure, and phylogeographic history. [ABSTRACT FROM AUTHOR]

We isolated and characterized 19 microsatellite loci from the endangered seaside alder, Alnus maritima. Loci were screened in 24 individuals of A. maritima and four individuals of its congener the hazel alder, A. serrulata. The number of alleles per locus ranged from 2 to 6, observed heterozygosity ranged from 0 to 0.952, and the probability of identity values ranged from 0.126 to 0.850. These new loci provide tools for characterizing the population genetics of this rare tree. [ABSTRACT FROM AUTHOR]

We isolated and characterized 12 microsatellite loci from the endangered Red Hills salamander, Phaeognathus hubrichti. Loci were screened in 24 individuals of P. hubrichti. The number of alleles per locus ranged from 2 to 16, observed heterozygosity ranged from 0.130 to 0.750, and the probability of identity values ranged from 0.012 to 0.778. These new loci provide tools for examining the population genetics of this federally threatened salamander. [ABSTRACT FROM AUTHOR]

We developed and optimized 15 polymorphic microsatellite loci in the jungle perch, Kuhlia rupestris. Loci were screened in a single population ( n = 24) from Fraser Island, Queensland, Australia. Number of alleles per locus ranged from 3 to 19 and observed heterozygosity from 0.25 to 1. No significant linkage disequilibrium was detected between any pair of loci. Genotype proportions for these loci in the population sampled were in Hardy–Weinberg equilibrium. [ABSTRACT FROM AUTHOR]

Ligumia nasuta (Say, 1817; Eastern Pondmussel) is an imperiled freshwater mussel (Unionidae) in eastern North America. Population declines in the Laurentian Great Lakes resulting from the introduction of dreissenid mussels and habitat destruction in the 20th Century have greatly reduced and limited its distribution. To properly inform restoration and management efforts for L. nasuta , fine-scale genetic analyses must be performed on the remnant populations. This study used Illumina paired-end shotgun sequencing to identify potential microsatellite loci for L. nasuta , utilizing two samples to develop the Illumina paired-end shotgun library. Forty-eight primer pairs were tested on the remaining 24 samples. Twenty-nine of the 48 microsatellite primer sets screened were successfully amplified using 24 L. nasuta samples collected from the Great Lakes watershed. The estimated fragment size ranged from 167 to 445 base-pairs (bp) and the number of alleles per locus varied between 5 and 16 (mean = 9.7). Only five of the loci deviated significantly from Hardy–Weinberg expectations after Bonferroni corrections. The development of these new microsatellite loci will greatly facilitate future genetic studies on L. nasuta . [ABSTRACT FROM AUTHOR]

Abstract: Earthworms are important components of soil ecosystems worldwide, and have been used extensively as indicator species in ecotoxicology studies. Our understanding of mating systems, population structure, and genetic diversity in earthworms is limited by the current lack of available genetic tools. To address this gap, we developed 16 novel microsatellite markers for the compost earthworm Eisenia fetida, one of the most widely studied earthworm species. We tested the new markers in 3 putative populations of worms from commercial vermiculture operations in Canada and the U.S.A. All 16 loci were variable in at least one population, with the number of alleles per locus ranging from 3 to 10, observed heterozygosity from 0.000 to 0.783, and polymorphic information content from 0.032 to 0.587. One group had significantly reduced heterozygosity compared to the other 2, but overall there were only minor genetic differences among the tested suppliers, suggesting a possible bottleneck for this species in North America. The microsatellite loci we describe here will be extremely useful tools for future field and laboratory studies of E. fetida. Body size and condition in adult worms varied significantly by supplier, and breeding success and cocoon production were significantly higher in breeding pairs from one supplier compared to the other two. In the absence of evidence for genetic divergence among populations, our results suggest that the early rearing environment may be an important factor affecting adult breeding performance. We caution that the source of worms may affect the outcome of laboratory experiments involving growth and reproduction. [Copyright &y& Elsevier]