Validation of a cheap and simple nondestructive method for obtaining AFLPs and DNA sequences (mitochondrial and nuclear) in amphibians

Abstract

The use of nondestructive methods for obtaining DNA from amphibians (e.g. buccal swabs) allows genetic studies to be performed without affecting the survival of the studied individuals. In this study, we compared two methods of nondestructive DNA sampling, buccal swabs and interdigital membrane or toe-clipping, in several amphibian species of different size: Rhinella spinulosa, R. atacamensis, six species of the genus Telmatobius and Pleurodema thaul. We evaluated the integrity of the DNA extracted by sequencing fragments of mitochondrial and nuclear genes and by generating amplified fragment length polymorphisms markers (AFLPs). In all cases, we obtained an adequate amount of DNA (mean range 55-298 ng/μL). We obtained identical DNA sequences from buccal swab and interdigital membrane/toe-clip for all individuals. The differences in the coding of AFLP markers between the tissues were similar to those reported for replicas of the same type of sample in similar analyses in other species of amphibians. In conclusion, the use of buccal swabs is a trustworthy and inexpensive method to obtain DNA for mitochondrial and nuclear sequencing and AFLP analyses. Given the types of markers evaluated, buccal swabs may be used for phylogenetic, phylogeographic and population genetic studies, even in small amphibians (<33 mm).