RESUMEN
There is substantial evidence showing that the polymorphism of the goat alphas1-casein (CSN1S1) gene has a major effect on milk protein, casein and fat content as well as on cheese yield. However, its influence on the synthesis rate of CSN1S1 has been less studied, with measurements only available in French breeds. In this article, we have measured milk CSN1S1 content in 89 Malagueña and 138 Murciano-Granadina goats with 305 and 460 phenotypic registers, respectively. In the Malagueña breed, average values of CSN1S1 content estimated for BB, BF, EE and FF genotypes were 6.94+/-0.38, 5.36+/-0.22, 4.58+/-0.13 and 3.98+/-0.27 g/l, respectively, being all significantly different (P<0.05). Conversely, in the Murciano-Granadina breed only the BB genotype (8.50+/-0.60 g/l) was significantly associated with increased levels of CSN1S1 (P<0.05), whereas BF (6.56+/-0.82 g/l), EE (6.39+/-0.60 g/l) and EF (6.91+/-0.76 g/l) genotypes displayed non-significant differences when compared with each other. Our results highlight the existence of breed-specific genetic and/or environmental factors modulating the impact of the CSN1S1 gene polymorphism on the synthesis rate of the corresponding protein.
Asunto(s)
Caseínas/genética , Cabras/genética , Leche/fisiología , Fragmentos de Péptidos/farmacología , Animales , Caseínas/farmacología , Cartilla de ADN , Exones , Femenino , Genotipo , Lípidos/análisis , Leche/química , Leche/metabolismo , Proteínas de la Leche/genética , España , Espectrofotometría InfrarrojaRESUMEN
A capillary electrophoresis (CE) method has been applied for the quantitative determination of alpha(s1)- and alpha(s2)-CN in goat's milk. Several analytical parameters were evaluated showing the reliability of this CE method. Coefficients of determination (R2) greater than 99% were obtained and determination limits of 1.23 and 0.98 mg/ml were achieved for alpha(s1)- and alpha(s2)-CN, respectively. The analytical parameters studied in terms of accuracy, precision and recovery were within acceptable limits. Among 18 samples of 4 different genotypes (BB, EE, BF and FF) for alpha(s1)-CN were analysed, different amounts were obtained from the genotypes.
