Molecular Characterization of Selected Native Sheep Using Rapd Markers

Abstract

Sheep is one of the important domestic animals in Bangladesh. Genetic improvement of this animal is economically important, especially for reproductive performance and the quality of meat, wool, and milk. Genetic similarity and polymorphism among sheep populations from three different areas were studied using the Random Amplified Polymorphic DNA (RAPD) technique. The research was conducted at the Animal Cell Culture and Molecular Biotechnology Laboratory, Khulna University, Bangladesh, to evaluate genetic variation among sheep from different regions of Bangladesh. Twenty blood samples were collected from the Bangladesh Livestock Research Institute Sheep Farm, Savar, Dhaka. The quality and quantity of DNA were determined by agarose gel electrophoresis and spectrophotometry. RAPD-PCR was employed to assess genetic variability among the sheep populations. PCR reactions were carried out using 10 random oligonucleotide primers, of which three produced distinctive and reproducible bands. A total reaction volume of 20 µl was used for PCR. The reaction mixture consisted of 2 µl DNA sample (2 ng/µl), 2 µl of 10× reaction buffer, 2 µl of Tag DNA polymerase (1 unit/µl), 1 µl of oligonucleotide primer (100 pico mol/µl), and 11 µl of distilled water. RAPD patterns with a polymorphism level of 89.63% were detected among the sheep populations. Genetic distance and dendrograms were determined using COMPONENT 2.0 software. Of the 19 distinct bands obtained, 17 were polymorphic. Tangail (L095) showed comparatively higher genetic distance (1) from Naogaon (IB05), (IB16), (IB03), and (IB10). Similarly, Naogaon (IB16) showed a genetic distance of 1 from Tangail (J02) and Noakhali (OC23). Moreover, Noakhali (IC02) showed the highest genetic dissimilarity with Naogaon (IB05). The results suggest that RAPD-PCR can be successfully used to analyze genetic variation and similarity among sheep populations from different regions. Although some phenotypic differences exist among genetically similar sheep, such variations may be attributed to environmental effects.