Mitochondrial cytochrome B gene based phylogenetic analysis of Nilgiri langur (Semnopithecus johnii) sampled from Periyar Tiger reserve, Kerala

The Western Ghats, a biodiversity hotspot in peninsular India, serve as a critical habitat for the vulnerable Nilgiri langur (Semnopithecus johnii), endemic to the region. This study explores the phylogenetic placement of S. johnii populations based on the mitochondrial CYTB gene (857 bp) sequences. Briefly, twelve faecal samples were collected from three sites within Periyar Tiger Reserve (PTR), Kerala. The DNA was isolated from the faecal samples and the CYTB gene was amplified and sequenced. The sequences were subjected to phylogenetic analyses using Maximum Likelihood, Bayesian Inference and Neighbour-Joining methods. All the methods revealed a well-supported monophyletic clade comprising PTR sequences and additional S. johnii and S. priam sequences retrieved from NCBI sampled from Aanamalai, Silent Valley and Walayar. The PTR populations clustered into three subclades with moderate support, while one sequence formed a distinct lineage, indicating genetic differentiation within populations. These findings corroborate earlier molecular studies, supporting the classification of S. johnii under the genus Semnopithecus.