Accuracy in molecular sexing of martens (Martes americana and Martes caurina) varies among sample types

Abstract

We evaluated the accuracy of sex identification using the SRY marker for American marten (Martes americana) and Pacific marten (Martes caurina) using samples collected from commercial trappers and those obtained via noninvasive sampling. We determined that sex identification from Lut-SRY primers is accurate at >90% for muscle and hair samples collected noninvasively. We found much lower accuracy when using hair samples plucked from trapper-killed carcasses, errors presumably incurred from contamination from the DNA of trappers, who were entirely male. We also found that the sequence generated from Lut-SRY primers, originally developed for Eurasian otters (Lutra lutra), differed slightly for martens, and recommend that new primers be developed from the sequences we provide. The SRY marker can be reliably used for sex identification in both species of marten, provided that samples have low probabilities of contamination. Researchers should avoid samples collected from external locations on trapper-killed carcasses for DNA-based analyses.

Modest immigration can rescue a reintroduced carnivore population

“…We then genotyped template DNA of the samples using 10 (Nicolet; Grauer et al ) and 14 (Chequamegon; Manlick et al ) previously developed microsatellite markers (Williams et al ) using GeneMapper v4.5 software (Applied Biosystems) following previous protocols (Grauer et al ). We determined individual sex using a species‐specific SRY marker analyzed on an electrophoretic gel (Campbell et al ). We ran all samples in a minimum of 3 independent polymerase chain reactions (PCRs) to minimize genetic errors such as allelic dropout and peak irregularities (Taberlet et al , Bonin et al ).…”

Genetic sex determination assays in 53 mammalian species: Literature analysis and guidelines for reporting standardization

“…Therefore, the simplex assay possesses an advantage in terms of preparation time and costs (Clapcote & Roder, 2005). The automatization of detection with the use of fluorescently labeled primers has even further eased the sexing process (Sullivan et al., 1993) as well as the visualization of results with capillary techniques reducing potential human mistakes and increasing throughput analysis (Campbell et al., 2010). Development of new tests could be speeded up as already defined assays can be used on additional species due to interspecies homology between sequences, but this potential is currently largely neglected.…”

“…Higher sensitivity and thus detection of low amounts of DNA can be achieved with loop-mediated isothermal amplification (LAMP) (Lee, 2017). An approach for reducing cross-contamination is the use of certain sample types that are less prone to containing impurities, for example, the use of muscle tissue instead of hair (Campbell, Pauli, Thomas, & McClean, 2010). Molecular sexing is especially important in rape victim identification as an alternative to spermatozoa detection, which can produce false negatives due to condom use or lack of ejaculation.…”