GENETIC POLYMORPHISMS OF α_S1-CASEIN (CSN1S1) AND β-CASEIN (CSN2) GENES IN CARPATHIAN GOAT BREED

V.A. Balteanu, C. Pascal, A. Vlaic

Abstract
    In goat casein loci a large genetic variation was described with up to 20 alleles found at the α_S1-casein (CSN1S1) locus and 9 alleles at the β-casein (CSN2) locus. In Carpathian goat breed little is known about the nucleotide variations occurring at the CSN1S1 and CSN2 loci. Therefore the objective of this study was to identify the types of alleles occurring at these loci in a Carpathian goat population by using proteomic and genomic analysis tools. Isoelectric focusing (IEF) analysis of milk samples allowed the identification of some CSN1S1 variants (A, B/E, C and F) based on isoelectric point differences. Furthermore AS-PCR genotyping test allowed the discrimination of E from non-E alleles. The sequencing of CSN1S1 and CSN2 cDNA obtained from some goats from the analysed population revealed that the IEF bands attributed to CSN1S1 B contains two variants (B2 and B4), while the monomorphic IEF CSN2 pattern contains the A and C variants. However the variation of CSN1S1 and CSN2 loci in Carpathian goat breed could be more complex and therefore further studies on a larger number of goats are needed to characterize it.

Key words: goat, milk, casein, polymorphisms, alleles