Detection of Single Nucleotide Polymorphism by T-ARMS PCR of Cross Bred Cattle Karan Fries for A1, A2 Beta Casein Types

Abstract

“Detection of Single nucleotide Polymorphism by T-ARMS PCR of cross bred cattle Karan Fries for A1, A2 beta casein types” to distinguish between A1 and A2 type containing beta-casein and genotyping of hundred Karan Fries cross breed cattle. Casein is the main milk protein where it accounts for 80% of bovine milk protein and contains four fractions (alpha S1-CN, alpha S2-CN, beta-CN and k-CN). Beta casein contributes 25-35% of milk protein and many variants are reported (A1, A2, A3, B, C, D, E, F, G, H1, H2 and I) in different breeds of cattle. The beta casein variants A1 and A2 differs in the 67th amino acid position, the substitution of proline in A2 type with Histidine (in A1) is mainly due to a replacement of “C” nucleotide with “A” nucleotide in that corresponding nucleotide position. One hundred Karan Fries cross breed cattle were selected for genotyping of A1, A2 beta casein gene from the genomic DNA. The beta casein gene was amplified by Multiplex Tetra-Primer Amplification (T-ARMS-PCR). T-ARMS touchdown PCR and subsequent agarose gel electrophoresis could differentiate between the A1, A2 types of beta casein genes in these animals. The screening result showed three genotypes of animal in these 100 animals. The number of A2A2, A1A2 and A1A1 animals are 73, 19 and 8 respectively. The frequency of A2 and A1 alleles are 0.825 and 0.175 respectively