ANALYSIS OF BETA-CASEIN GENE VARIANTS IN BUFFALO OF BOCHASAN FARM THROUGH PCR-RFLP

Abstract

Bovine milk and dairy products play a significant role in traditional diets worldwide. Bovine milk protein consists of 80% casein and 20% whey. β-casein is the most common hydrophobic casein found in bovine milk. It has 2 frequent variants, A1 and A2. The only structural variation between the two beta-caseins is the location of amino acid 67, where histidine (CCT) in A1 is substituted by proline (CAT) in A2. The study was undertaken to analyze bovine β-casein variants in a total of 105 Jaffarabadi buffalo of Bochasan farm using polymerase chain reaction-restriction fragment length polymorphism. Genomic DNA was successfully isolated using Phenol-Chloroform-Isoamyl alcohol method. Quality and quantity analysis was done by Agarose gel electrophoresis and Nanodrop respectively. The DNA was amplified using PCR that yielded 121bp fragment. Genetic polymorphism was detected by digesting PCR products using restriction endonuclease Dde I. Restriction digestion with Dde I revealed two genotypes: A1A2 and A2A2. The genotypic frequencies of A1A2 and A2A2 genotypes were 0.25 and 0.75 respectively. A1A1 genotype was absent in the studied population. The allelic frequency was 0.13 for A1 allele and 0.87 for A2 allele. These results confirmed that Jaffarabadi buffaloes predominantly have A2 milk.