Genetic documentation of snake species using non-invasive sampling and non-toxic DNA isolation method

Despite the knowledge of the evolution of snakes worldwide, snake phylogeny requires a more detailed approach in South India. Molecular taxonomic approaches using DNA barcoding are a molecular tool frequently in species identification as well as studies of phylogenetics. Here, a non-invasive genetic sampling method using skin exuviates was used. This method is often overlooked for molecular studies of reptiles. We isolated DNA using a non-toxic method from skin exuviates collected from Chennai Snake Park and screened for the cytochrome oxidase subunit I (COI) region of mitochondria. Samples that were amplified successfully were barcoded. A total of seven species of snakes were identified which belonged to 5 families. We combined and compared sequences of these seven-snake species from other countries to construct a phylogenetic tree and examined the genetic distance within species and families. This depiction and analysis showed a high degree of genetic variability intra-specifically between the South Indian samples to the samples from other parts of the world. This study documents how skin exuviates of snakes and the polymerase chain reaction of the COI region can be used for DNA barcoding and estimating phylogenetic relationships among snake species. Overall, this method is very versatile, inexpensive, and non-toxic which can help in understanding the evolution and phylogeny of snakes to formulate proper strategies for the conservation of snake species.