Calpastatin (CAST) gene polymorphism in Kajli, Lohi and Thalli sheep breeds
Calpastatin-encoding gene (<i>CAST</i>) is located on the fifth chromosome of sheep and it plays an important role in the development of muscles and in meat tenderness. The present study was conducted to investigate a calpastatin (CAST) gene polymorphism in Pakistani Thalli, Lohi and Kajli sheep breed. Random blood samples were collected from 300 animals (100 samples from each Thalli, Lohi and Kajli breeds). Genomic DNA was extracted using phenol-chloroform extraction method. A 622 bp CAST gene segment (exon 1C/1D region) was amplified by polymerase chain reaction (PCR) using ovine specific primers. Restriction fragment length polymorphisms (RFLPs) in the amplified fragments were studied using Msp1 restriction enzyme. Frequencies of MM, MN and NN genotypes were found to be 77, 20 and 3% in Lohi breed and 68, 26 and 6% in Kajli breed respectively. In Thalli sheep, only the MM (80%) and MN (20%) genotypes were detected. Chi-Square test (p < 0.05) showed that all the three populations used in this study were in Hardy-Weinberg equilibrium. By comparing the results of this study with those of previous studies, it seems that the MM genotype is the dominant genotype and the M allele is the dominant allele in small ruminant breeds belonging to different geographical locations.
Key words: Thalli, Lohi, CAST gene, Kajli, polymorphism, Msp1, PCR-RFLP.