Population Genetic structure and Phylogeny of Himalayan Gorals ( Naemorchedus goral) in central nepal

Abstract

Gorals (Naemorhedus spp.) are facing taxonomic incongruence due to morphological variations and phylogenetic disparities among the studies mainly due to incomplete lineage sorting. The Himalayan region is believed to have two species/subspecies of Himalayan gorals (Naemorhedus goral), however the population in Nepal remains excluded in phylogenetic studies. Limited studies have been conducted in gorals of Nepal which focus on distribution, threats, and conservation of Himalayan gorals, however, the genetic information is yet to be explored. This study aimed for understanding the genetic structure in Central Nepal and establishing the phylogenetic relationship of Himalayan gorals within the subfamily Caprinae. Fecal samples were collected from Langtang National Park and Gaurishankhar Conservation Area representing the Himalayan range and from Daunne Forest that lies in Nawalparasi district in the Mahabharat range. Mitochondrial cytochrome b (1002 bp) and control region (1069 bp) gene sequences were used as molecular markers. Population genetic analysis of the three subpopulations from Central Nepal along with phylogenetic analysis was performed to clarify the genetic characteristics, taxonomy, and phylogeny of Himalayan gorals. As a result, from twenty-nine sequences, five novel haplotypes of mitochondrial cytochrome b were identified, exhibiting low haplotype diversity (0.3960) and very low nucleotide diversity (0.0006). In contrast, 14 novel haplotypes of control region were identified with high haplotype diversity (0.8200) and moderate nucleotide diversity (0.0082). The median joining haplotype network was star-shaped indicating a recent population expansion with bottleneck or founder effect. The maximum likelihood (ML) tree of the obtained haplotypes, along with partial sequences from the Indian Himalayan region indicated that the haplotypes from Central Nepal are more closely related to those from Sikkim (Eastern Himalaya) than those from Uttarakhand (Western Himalaya). The maximum likelihood tree of the genus Naemorhedus suggested six valid species of gorals. The Bayesian time tree of mitochondrial cytochrome b within the subfamily Caprinae revealed that the genus Naemorhedus is most closely related to the genus Capricornis and next to the genus Ovibos. It is important to know the level of genetic diversity the goral populations in Nepal possess and identify some genetically unique subpopulations of conservation importance.