A new minimally invasive and inexpensive sampling method for genetic studies in pinnipeds
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The choice of sampling method is essential in the development of a population genetic study. This choice influences the type of samples that can be obtained and, therefore, the quality of the extracted DNA. Sampling methods can be classified into invasive, non-invasive, and minimally invasive. This last category is preferred, as it minimizes handling, damage, and degree of disturbance to animals, while still providing enough DNA for genetic studies. Here, we describe a very low cost and easy to manufacture minimally invasive sampler, developed to obtain hair samples from pinnipeds. The sampler was highly effective both at reaching animals and collecting a good number of hairs. We compared the efficiency of hair samples obtained using our device, versus tissue samples collected from dead animals, by counting successful mtDNA amplifications and sequencing. Hair samples amplified more efficiently compared with tissue samples, but sequencing was equally efficient for both sample types. In conclusion, the sampler described is an excellent option to obtain DNA for genetic studies. This minimally invasive technique can also be used to sample hair for other studies, such as estimation of environmental contaminants, measurement of individual hormone levels, or diet determination through the analysis of stable isotopes, among other potential uses.
KeywordsSampling methodology Pinnipeds Population genetics Molecular ecology Field techniques
We thank Guillermo H. Cassini for his help with the statistical analysis, Connie Ranieri for her help in developing the idea, and Lida Pimper for her help in logistic and permits request. We also thank the Park Rangers of Monte León National Park for their collaboration and hospitality, the Consejo Agrario de Santa Cruz for the facilities they gave us to work, and the CADACE members who treated us very well during our stay. Finally, we would like to thank Shirley Espert and Luciano Valenzuela for their help with language corrections and to the three anonymous reviewers who help us to improve the manuscript. This study was supported by grants and fellowships from National Geographic Society, Universidad Nacional de Luján, and CONICET.
This study was funded by a National Geographic Society Young Explorer grant (number 10000-16).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
All applicable international, national and/or institutional guidelines for sampling, care, and experimental use of organisms for the study have been followed, and all necessary approvals have been obtained (detailed below). Asociación Parques Nacionales (APN), Research Permission 114-CPA 2017; Dirección de Fauna Silvestre Provincia de Santa Cruz, Disposición No. 01/2017.
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