RESUMEN
Stearoyl-CoA desaturase (SCD) plays a key metabolic role by changing the saturated FA content of ruminant milk and meat. In this study we characterized for the first time the stearoyl-CoA desaturase (SCD) gene in river buffalo (Bubalus bubalis) and investigated its genetic variability. On a total of 78 buffaloes, 15 SNPs were detected and 6 of them were preliminarily genotyped. In particular, the g.133A>C SNP was found to create a new consensus site for the SP1 binding site, thus generating a new tandem repeat in the promoter region. A preliminary association study with the milk fatty acid content showed that the C allele significantly affects the total desaturation index (P<0.01). Linkage disequilibrium analysis allowed identification of 7 haplotypes and 4 tag SNPs. Such polymorphisms could represent useful genetic markers for association studies with fatty acid composition, but further studies are needed to evaluate their potential use to improve the nutritional quality of the dairy products.
Asunto(s)
Búfalos/genética , Variación Genética , Ríos , Análisis de Secuencia de ADN/métodos , Estearoil-CoA Desaturasa/genética , Animales , Ácidos Grasos/metabolismo , Frecuencia de los Genes/genética , Genotipo , Haplotipos/genética , Italia , Análisis de los Mínimos Cuadrados , Desequilibrio de Ligamiento/genética , Mar Mediterráneo , Datos de Secuencia Molecular , Polimorfismo de Nucleótido Simple/genéticaAsunto(s)
Empalme Alternativo/genética , Búfalos/genética , Caseínas/genética , Leche/química , Animales , Secuencia de Bases , Cruzamiento , Cromatografía Líquida de Alta Presión , Cartilla de ADN/genética , ADN Complementario/genética , Femenino , Frecuencia de los Genes , Italia , Datos de Secuencia Molecular , Mutación Puntual/genética , Polimorfismo de Longitud del Fragmento de Restricción/genética , Sitios de Empalme de ARN/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/veterinaria , Análisis de Secuencia de ADN/veterinariaRESUMEN
So far, at least eight alleles in the goat CSN2 locus have been associated with the level of beta-casein expression in milk. Alleles CSN2(A), CSN2(A1), CSN2(B), CSN2(C), CSN2(D) and CSN2(E) have been associated with normal content (allele effects of about 5 g of beta-casein per litre), whereas the CSN2(0) and CSN2(01) alleles have been associated with non-detectable levels of beta-casein. Most of these alleles have been characterized genetically. Herein, we report the identification of a previously unreported SNP in the goat CSN2 promoter region (AJ011018:g.1311T>C), which is associated with the absence of beta-casein in the milk. Furthermore, we developed a PCR-based method that allows detection of this mutation.