Polymorphism of stearoyl-coenzyme A desaturase 1(SCD1) gene in Iranian Holstein dairy cattle.

The aim of this study was to investigate the polymorphism of SCD1 gene in Holstein dairy cattle. The identification of alleles of loci associated with important function in animal metabolism could assist in recognizing potential molecular marker for dairy cattle milk production traits. Milk is essential for energy, protein, minerals and vitamins for the young stock in the early phase of their life. The SCD1 gene, expressed in adiposities mammary glands and also in other tissues, encodes a key enzyme which is responsible for converting palmitic and stearic acids into their monounsaturated forms. Additionally, the SCD1 protein was shown to be involved in some aspects of energy homeostasis e.g. lipogenesis, lipid oxidation, and thermo genesis. The SCD1 gene is located on chromosome 26 in cattle. The blood samples of 394 dairy cattle from four farms were used for extracting genomic DNA. A 400 bp fragment of exon 5 of SCD1 gene was amplified by standard PCR, and digested with NcoI enzyme for recognizing the SNP (C/T). The cytosine to thymine substitution causes Alanine to change to Valine amino acids on protein (A293V). The frequency of AA, AV and VV were 0.6015, 0.3173 and 0.0812 respectively. The frequency of alleles A and V were 0.76 and 0.24 respectively. The results of chi square test showed that the population was not under Hardy Weinberg equilibrium.