Genetic polymorphism of the calcium sensitive caseins in sicilian Girgentana and Argentata dell'Etna goat breeds

The genetic polymorphism of calcium sensitive caseins was investigated in two endangered Sicilian goat breeds. The study was carried out on 524 goats (341 Girgentana and 183 Argentata dell'Etna) by means of different PCR, AS-PCR and PCR-RFLP reactions. The analysed loci (CSN1S1, CSN1S2 and CSN2) were found to be polymorphic in both breeds. Girgentana seems to be less polymorphic than Argentata: 7 and 9 alleles, 12 and 17 genotypes, 3 and 4 haplotypes were identified in Girgentana and Argentata dell'Etna, respectively. The allelic and genotypic distribution was different in the two breeds, particularly at αs2 and β-casein loci (P < 0.001). The trials on the three calcium sensitive casein loci made it possible to assess the effect of the quantitative alleles on both the quality and on the content of casein in milk produced by these two Sicilian goat breeds.