Il Gene SREBP-1 e le caratteristiche del latte in ovini di razza Sarda

SREBF are a family of transcription factors structurally related that play an important role in the lipid homeostasis adjusting the expression of genes involved in cholesterol, fat acids, triglycerides and phospholipides synthesis. Nowadays 3 SREBP isoforms have been discovered: 1a, 1c and 2. 1c isoform is involved in the fat acids synthesis and in the insulin-induced metabolism, 2 isoform is specific in the cholesterol biosynthesis while 1a is involved in both way. The aim of this research was to characterize the entire coding sequence of SREBP-1 gene in Sarda breed sheep and to evaluate the association between SREBP-1 gene polymorphism and production traits. We used 80 Sarda breed sheep of 2 farm located in north Sardinia with the same food and management condition. Daily milk yield for each animal was determined and also milk samples (50 ml each) were collected to laboratory analysis. 10 ml of blood were collected from each animal to extract DNA genomic. 19 couple of primers were used to amplify the entire coding sequence. SSCP analysis (Single Strand Conformation Polymorphism) was used to resolve the PCR products. We discovered 8 SNPs. The polymorphism localization are as follow: G980T, G981T, C1686T, C5448T, G5657A, G5688A and C6872T. 12 haplotypes were found but only 7 showed a frequency over 0,02. No correlation was found between SNPs and milk traits. None significant association between 7 haplotypes and milk traits were detected.