Variation of prolactin and β-Lactoglobulin genes in the Indonesian FH Cattle

Abstract

Prolactin is a polypeptide hormone, encoded by the prolactin (PRL) gene, synthesized and secreted by anterior pituitary, and affecting milk yield and composition. β-Lactoglobulin (BLG) is the major whey proteinin the milk of ruminants. This study was conducted to identify the PRL and LGB genes polymorphism in the Indonesian FH cattle. A total of 139 individual cattle blood samples from West Java were used to obtain DNA samples through the DNA extraction process. Identification of the PRL and LGB genes was performed using PCR-RFLP method with RsaI (PRL gene) and HaeIII (BLG gene) restriction enzymes. The PRL gene was amplified using forward primer 5’-ccaaatccactgaattatgctt-3’ and reverse primer 5’-acagaaatcacctctctcattca-3’. The BLG gene was amplified using forward primer 5’-tgtgctggacaccgactacaaaaag-3’ and reverse primer 5’-gctcccggtatatgaccaccctct-3’. The PRL and BLG genes in the Indonesia FH cattle were polymorphic based on the PCR-RFLP analysis but the heterozygosity value was low. There were two alleles (G and A) and three genotypes (GG, GA, and AA) identified in the PRL gene of the Indonesian FH cattle with genotype frequencies were 0.914, 0.079, and 0,007 for GG, GA, and AA genotypes respectively. There were two genotypes (CC and CG) identified in the BLG gene with genotype frequencies were 0.91 (CC), and 0.09 (CG). Information about the PRL and BLG genes polymorphism in this study can be considered for further study to analyse its association with milk yield trait.