Β-Lactoglobulin gene polymorphism in exon 2 association with milk economic traitsin buffaloes of East Azarbaijan province by PCR- RFLP technique

Milk production traits and its components are belong to quantitative and polygenic traits and affected by many genes. This study was aimed to determine the β-Lactoglobulin gene polymorphism and its relationship with milk composition in a population of buffaloes in the East Azarbaijan province. Milk samples were collected from 70 buffaloes of East Azarbaijan province and then DNA samples were extracted using pronase method. After DNA extraction gene specific primers used for amplification of 452 bp fragment for Exon 2 of Beta-lactoglobulin gene. Genotypes were determined by PCR-RFLP method followed by treatment with RsaI restriction enzyme. To investigate the association of Beta-lactoglobulin gene polymorphism with milk composition (fat, protein and lactose), the GLM procedure of SAS software was used. Three genotype patterns including AA, AB and BB were observed with the frequencies of 88.87, 10.5 and 0.83, respectively. The population deviated from Hardy–Weinberg equilibrium. The effect of Beta-lactoglobulin gene polymorphism on milk composition was not significant. It Seem that repeated results obtained from further research in the future studies, (of higher sample sizes) it may be possible to use either this marker site or other sites (relevant to Beta-lactoglobulin gene) in selection programs as based on molecular DNA markers.