Identification of CSN1S1 Gene Variations Between Dairy Goat Breeds and its Influence on Milk Protein Fractions in Indonesia

Abstract

The CSN1S1 gene variation may cause the discrepancy of αs1 casein. The information was lacking on Peranakan Ettawa (PE), Saanen (SA), and Sapera (SP). The objective of this study was to reveal the variation and its expression in those breeds. RFLP-PCR (XmnI) was applied to identify A, F, and N alleles with AS-PCR for the E allele on 44 PE, 121 SA, and 15 SP does then sequencing. SDS-PAGE fractionated then quantified the milk proteins from 34 PE, 57 SA, and 15 SP does. The study found the A allele was predominate followed by F and N on PE and SA. However, the SP goat only has A and F alleles in equal frequency, and the E allele was only found on SA. The AF genotype predominated on all breeds in almost half of its population, thus, the most diverse was SA. The Hardy-Weinberg disequilibrium of PE and SA indicated the influence of the breeding program. The genotypes affected the αs1 casein, total casein, and αs1/β ratio, in which AA was highest. The A, F, and N allele expressions were 3.21, 0.82, and 0.60g/L, respectively. It can be drawn that the CSN1S1 gene variation has occurred in those breeds and an intermediate-expressing genotype was predominant, which affected the amount of some milk protein.