Association of the CSN1S1 gene polymorphism with milk composition traits in Jamunapari goat

Abstract

The genetic polymorphism of the CSN1S1 (casein alpha-s1) locus was investigated in Jamunapari goat breed by Sodium Dodicyle Sulphate – Poly Acrylamide Gel Electrophoresis (SDS-PAGE) and Polymerase Chain Reaction – Restriction Fragment Length Polymorphism (PCR-RFLP). A total of 122 milk and blood samples were collected. The SDS-PAGE pattern revealed the presence of four variants of CSN1S1 locus namely, A, B, E and F. The A allele of a-s1 – casein was observed in the majority of goats. The genotypic frequency of the AA, BB, BE, AF and FF genotypes of CSN1S1 locus were 0.437, 0.175, 0.250, 0.125 and 0.012, respectively. The PCR-RFLP was performed, six different variant groups of F allele (224)bp, the B/E allelic pair (161+63) bp, A/0 allelic pair (150+63) bp, AD allelic pair (212+150+63) bp, AF allelic pair (224+150+63) bp and BF allelic pair (224+160+63) were obtained after restriction digestion with XmnI. The genotypic frequency of AA, AD, AF, BB, BE, BF and BC genotypes were 0.274, 0.114, 0.147, 0.098, 0.163, 0.081 and 0.163, respectively. The allelic frequency of A, B, C, D, E and F were 0.360, 0.303, 0.081, 0.057, 0.081 and 0.114, respectively. The present study showed that AA genotype had significant effect on total protein content on the milk and AD genotype had significant effect on 90 day milk yield in Jamunapari goat. Thus the CSN1S1 genotype information in Jamunapari could be utilised in selection strategies, in order to select genetic stock for the production of goat milk with higher protein content in marker assisted selection to increase the rate of genetic gain.