Characterization of 12 polymorphic microsatellite loci for eastern chipmunks (Tamias striatus)

Eastern chipmunks are small forest rodents for which ecological data at multiple spatial scales exist, but no molecular markers have been developed that provide adequate resolution to examine genetic structure at fine scales in this species. Thus, we developed 12 variable microsatellite loci, which amplified in three multiplexed reactions, and screened them in 27 individuals from northern Indiana, USA. Observed heterozygosities across loci ranged from 0.26 to 0.91 and number of alleles per locus ranged from three to 10. We will use these markers along with ecological data to understand population dynamics of eastern chipmunks at small spatial scales.     

Development of 14 multiplexed microsatellite loci for raccoons Procyon lotor

In order to complement ecological information with genetic data we isolated and characterized 14 polymorphic microsatellite markers from raccoons (Procyon lotor). Three multiplexed panels comprising the loci were developed and 29 individuals from a contiguous habitat patch in northern Indiana, USA were genotyped. The number of alleles per locus ranged from four to 18, and overall heterozygosities ranged from 0.31 to 1.00. One locus was identified as possibly being X‐linked, since males appeared to be hemizygous. Data generated using these markers will be used to further our understanding of small‐scale raccoon population dynamics in a highly fragmented landscape.     

Ten new polymorphic microsatellite loci for North American river otters (Lontra canadensis) and their utility in related mustelids

We describe 10 novel North American river otter (Lontra canadensis) polymorphic microsatellite loci. Individuals from two river drainages in New York were sampled, and the number of alleles per locus ranged from two to 12 (Drainage 1) and two to 10 (Drainage 2). Observed heterozygosities ranged from 0.21 to 0.83 (Drainage 1) and 0.20 to 0.80 (Drainage 2). Preliminary screening revealed that loci amplified in five other mustelids [Martes pennanti (n = 6), Martes fiona (n = 8), Mustela frenata (n = 8), Mustela erminea (n = 8) and Mustela vison (n = 5)].     

Novel microsatellite loci for the study of the black‐capped vireo (Vireo atricapillus)

We identified 14 novel polymorphic microsatellite loci in the black‐capped vireo (Vireo atricapillus). We also attempted to amplify and genotype these loci in other Vireo species, including the white‐eyed vireo (Vireo griseus), red‐eyed vireo (Vireo olivaceus), and blue‐headed vireo (Vireo solitarius). In 33 genotyped black‐capped vireos from two locations, total alleles ranged from six to 20, with observed heterozygosity ranging from 0.58 to 0.91 and expected heterozygosity from 0.65 to 0.93. Two loci had detectable levels of null alleles. Many of the loci were able to be amplified in the related Vireo species.     

Evaluating levels of PCR efficiency and genotyping error in DNA extracted from engorged and non‐engorged female Dermacentor variabilis ticks

Polymerase chain reaction (PCR)‐based methods are increasingly used to elucidate tick biology. However, DNA extracted from ticks may provide poor PCR templates as a result of PCR inhibition by mammalian blood or contamination by male DNA (in fertilized females). In this study, the effects of removing the bloodmeal and reproductive organs were evaluated through paired DNA extractions in engorged and non‐engorged Dermacentor variabilis (Say) (Acari: Ixodidae), prior to PCR amplification at 12 microsatellites. The first extraction utilized only mouthparts and legs (‘mouthpart’ samples) and the second utilized tick bodies (‘body’ samples). The results indicated that contamination by male DNA was an unlikely source of genotyping error in mouthpart and body samples. Engorged females showed higher levels of PCR inhibition in body vs. mouthpart samples, with a 29% decrease in amplification success rates per PCR and a 10‐fold increase in levels of missing genotypes in body samples. By contrast, non‐engorged females showed little difference in amplification success rates or numbers of missing genotypes in body vs. mouthpart samples. We discuss analytical concerns related to this systematic bias in PCR problems and recommend the removal of the bloodmeal and reproductive organs prior to DNA extraction, especially in engorged female ticks.