Characterization of four indigenous sheep breeds of Balochistan, Pakistan by random amplified polymorphic DNAs
Genetic diversity among four indigenous breeds of sheep namely Mengali, Balochi, Beverigh and Harnai of Balochistan was detected by random amplified polymorphic DNA (RAPD) technique. Nineteen RAPD primers were initially applied and seventeen were chosen for further analysis, based on band pattern quality, reproducibility and presence of bands. An average of 92 RAPD fragments were obtained by using 17 primers and out of the 36 fragments (39.13%) illustrated monomorphism while, 56 bands (60.87%) were polymorphic in all the four sheep breeds. The number of bands amplified in all the sheep breeds ranged from 2 to 10. The highest number of polymorphic loci 40 was observed in the Mengali breed, while the lowest 28 was in Balochi. Further, 33 and 31 polymorphic loci were seen in Beverigh and Harnai breeds, respectively. The overall gene diversity was highest in the Mengali (0.1474) while the lowest in Balochi breed (0.0998). Results of genetic similarities showed closer proximity between Balochi and Beverigh (0.992), Balochi and Harnai (0.992), and between Beverigh and Harnai (0.996). The resemblance was observed between Mengali and Balochi (0.918), between Mengali and Beverigh breeds (0.931) and between Mengali and Harnai breeds (0.925). The high level of genetic similarity between Balochi, Beverigh and Harnai sheep indicated the close relationship that might be due to common habitat. Further the present study highlighted the presence of diversity among and within breeds that can be used in the selection or crossbreeding programs of sheep. The present study suggests that RAPD-PCR can effectively be used to determine the genetic distances among the sheep breeds.
Key words: Genetic distance, polymorphism, random amplified Polymorphic DNA.