GENETIC POLYMORPHISM OF β-CASEIN EXON 7 IN BUFFALOES (Bubalus bubalis)

Abstract

A1 and A2 are the most commonly observed milk variants of β-casein. Between these two types of milk, there is a difference of one amino acid located at exon 7 that influences the release of beta-casomorphin-7 (BCM-7), a peptide that can affect the digestibility of susceptible consumers. Thus, this study aimed to screen the β-casein exon 7 polymorphism in local water buffalo population. A total of 195 buffaloes and 49 cattle were genotyped for A1 and A2 allele variants using Restriction Fragment Length Polymorphism (RFLP) method with DdeI restriction enzyme. Analysis of the reported SNP C/A at position 8101 (Genbank: X14711) revealed a 100% A2 allelic frequency in buffaloes and 0.55 A2 and 0.45 A1 in cattle. A 509 bp fragment of exon 7 was also sequenced to determine the SNP 8101 C/A. This study demonstrates that the buffaloes still retain wildtype A2 milk.