# Phylogenetic Relationship Between Two Squirrel Species, Callosciurus pygerythrus and Funambulus pennantii, Inferred From Mitochondrial Cytochrome b Gene Sequences

## TL;DR

This study uses mitochondrial DNA to explore the genetic relationship between two squirrel species in Bangladesh, aiding conservation efforts.

## Contribution

The study provides new genetic insights into the phylogenetic relationship of Callosciurus pygerythrus and Funambulus pennantii using cytochrome b gene sequences.

## Key findings

- C. pygerythrus haplotypes form a single clade with 61% bootstrap support.
- F. pennantii haplotypes show close relatedness to Australian samples with 87% bootstrap support.
- The two species form distinct clusters due to genetic and morphological differences.

## Abstract

To investigate the phylogenetic relationship between two species of squirrels, the hoary‐bellied Himalayan squirrel Callosciurus pygerythrus and five‐striped palm squirrel Funambulus pennantii, at the population level to assist conservation and management, we analysed partial mitochondrial cytochrome b gene sequences (1140 base pairs). The hoary‐bellied Himalayan squirrels were collected from the Chittagong University campus and the Hazarikhil Wildlife Sanctuary, Chattogram, and the five‐striped palm squirrels were collected from the Rajshahi Zoo area of Bangladesh. Blood samples were collected from anaesthetized squirrels by expert veterinarians, drawing blood from femoral veins in accordance with proper protocols and permission from respective authorities for the PCR (polymerase chain reaction) study. Mitochondrial sequences from seven individual animals were submitted to the global NCBI (National Center for Biotechnology Information) database, retrieved seven accession numbers  (MT227570, MT252006, MT227571, MT227572, MT227573, MT227574 and MT227575), and data analyses using modern bioinformatics tools were conclusive in identifying the animals. The phylogenetic relationship between the two species was inferred from the partial mitochondrial cytochrome b gene of 1140 bp using Mega software in maximum likelihood methods. Results reveal a close genetic relationship among all haplotypes of C. pygerythrus within a single clade, supported by a high bootstrap value of 61%, providing insight into its systematic position. On the other hand, three subjected haplotypes of F. pennantii were observed to exhibit close relatedness to another two Australian haplotypes of F. pennantii sourced from the GeneBank, with a bootstrap value of 87%, contributing valuable insights into its systematic position. The divergence of the two species into distinct clusters on the phylogenetic tree is attributed to substantial morphological differences and significant genetic distances. Phylogenetic analysis among all available haplotypes to date among the two genera and species provides valuable analytical perspectives about intra‐ and inter‐specific relationships and quantifies the genetic diversity between Bangladesh and other geographic populations. The study emphasizes the necessity of conducting additional research with a substantial sample size to comprehensively investigate the genetic diversity of squirrel population in Bangladesh. The study will enhance our comprehension of wildlife biodiversity and contribute to the development of natural conservation strategies for these species. The global and local status of both of the species is ‘Least Concern’.

This study demonstrates the morphological as well as molecular study and phylogenetic relationship of two species of squirrel, the five‐striped palm squirrel and hoary‐bellied Himalayan squirrel. It also analyses the phylogenetic relationship among other squirrels based on cytochrome b gene of the two genera and species to assist conservation and management.