A preliminary study on the genetic diversity of small populations of two flying squirrel species from Pakistan (Hylopetes fimbriatus and Petaurista petaurista albiventer), based on mitochondrial DNA control region sequences

Abstract

We undertook a preliminary investigation on the population genetics of two flying squirrel species (Hylopetes fimbriatus and Petaurista petaurista albiventer) that are endemic to the northwestern Himalayan range. These species are distributed sympatrically, share similar ecological characteristics, and are confined to the Himalayan moist temperate forests ranging from 1350 to 3050 m elevation. To elucidate the genetic variability of small populations of these species, we determined the complete mitochondrial DNA control region sequence of H. fimbriatus (1109 bp) and P. petaurista albiventer (1051–1052 bp), collected at the Ayubia National Park of northern Pakistan. Haplotype and nucleotide diversities and average number of nucleotide differences among haplotypes of H. fimbriatus were similar to those of P. petaurista albiventer. However, transversional substitutions among haplotypes of H. fimbriatus were significantly greater than that of P. petaurista albiventer. This latter difference may have arisen from climatic changes during recent Pleistocene glaciations that differentially affected the distribution patterns of these two species. For instance, H. fimbriatus, which is more adaptive to colder and drier habitats, may have maintained a larger population base in the northwestern Himalayan range than P. petaurista albiventer. Alternatively, H. fimbriatus might have colonized the northwestern parts of the Himalayas earlier than P. petaurista albiventer, and may have had a longer evolutionary period to adapt to the cool mesic climate of this region.