Evaluation of Association between CSN2 Genetic Marker 7:32016718C>A with A1/A2 Milk in Pakistani Buffaloes

Milk is an essential part of the diet that plays an important role in human growth and development due to the presence of different components like calcium, fats and proteins. Among six major proteins of the milk, {beta}-casein is one of them which is being investigated here due to the A1/A2 milk genetic variants and its associated gene of CSN2 in one of the valued species of Bubalus bubalis in Pakistan. Fifty buffalo samples were genotyped using the ARMS-PCR technique. CSN2 gene locus 32016718C>A is located on Chr.7 with CDS position c.350C>A on its 7th exon as per (GenBank transcript ID: XM_006071124.3). In {beta}-casein, 117th amino acid position where histidine (CAT) is responsible for A1 and proline (CCT) for A2 milk phenotype. A2 milk is considered to be healthy for human health due to the absence of bioactive peptide {beta}-casomorphin-7 (BCM7) in comparison with A1 milk. The current results showed that overall, 100% buffalo population is homozygous wild-type (CC) which means no mutant allele is detected in all studied samples therefore, Pakistani buffalo is exclusively producing A2 milk. Furthermore, this work may also be conducted on different buffalo breeds in Pakistan as well as other species of cattle, goat, sheep and camel to explore their genomic architecture for this valued trait.