Molecular diversity and phylogenetic analysis of ten sheep breeds from Khyber Pakhtunkhwa, Pakistan, based on mitochondrial D-loop sequences

Livestock farming has a key role in many rural communities both economically and culturally. It plays an important role in overcoming the deficiencies of meat, milk, wool and various by-products. Pakistan has a large number of livestock, well-adapted to local conditions. and has some of the best tropical dairy breeds. Native sheep breeds stand a vital asset to the country's livestock sector because of their adaptability and unique genetic traits. However, knowledge of the genetic diversity of these sheep breeds remains limited. This study aims to investigate the genetic diversity of 10 local sheep breeds from Khyber Pakhtunkhwa by analyzing the mitochondrial D-loop from 159 individual samples of females. The sequenced data from the mtDNA D-loop showed 106 different haplotypes, with a haplotype diversity of 0.9854 ± 0.0041. Analysis of the mitochondrial D-loop revealed three distinct haplogroups (HapA, HapB, and HapC). Out of the 159 sequences, 125 (77.99%) grouped with HapA, 30 (18.87%) with HapB, and 5 (3.14%) with HapC. While HapA and HapB are commonly found in sheep breeds worldwide, the identification of 5 sequences belonging to HapC was unexpected. This haplogroup was seen in four sheep breeds: Afghani, Australian, Gauder and Waziri. Most interestingly, the two Pakistani-origin breeds, the Waziri sheep breed, from South of Waziristan and the Gauder, a crossbreed, have been identified with HapC haplogroup. This indicates that the sheep breeds of Khyber Pakhtunkhwa belong to three distinct phylogenetic lineages, suggesting a probable gene flow from the southwest to the northeast regions of the province.