Development and application of a molecular sexing protocol in the climate change-sensitive American pika
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Non-invasive sampling paired with molecular sexing provides a valuable tool for the study of elusive mammals, yet species-specific assays are required to ensure accurate identifications. The American pika (Ochotona princeps) is one example, having emerged as a focal mammalian species for studies of metapopulation dynamics and extinction risk in the face of climate change. Despite extensive study, knowledge of sex-specific patterns has been limited to small sample sizes given the need for live-trapping and field-based sexing. Here we describe a molecular sexing protocol designed to reliably determine sex from non-invasively collected hair. Our polymerase chain reaction-based method co-amplifies a male-specific sex-determining gene Y fragment and a species-specific autosomal microsatellite, the accuracy of which was validated on 15 internally-sexed individuals. Subsequent application to 157 hair samples demonstrated high rates of amplification success (96.0 %) and unambiguous sex determination (94.7 %), revealing a strong male-bias in the sample and one instance of inaccurate, field-based sex identification.
KeywordsSRY Ochotona princeps Non-invasive Conservation genetics
Joanna Varner, Cheryl Blair and Karl Larsen provided samples of known sex. Funding was provided by an NSERC Discovery Grant #341711–07 (MR) and UBC Okanagan in the form of an Undergraduate Research Award from the Barber School of Arts and Sciences (CL), and an University Graduate Fellowship (KR).
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