Novel single nucleotide polymorphisms in the 5' regulatory region of the duck SCD1 gene and their associations with serum biochemical levels and fatty acid composition.

Stearoyl-coenzyme A desaturase 1 (SCD1) is the key limiting enzyme in the synthesis of monounsaturated fatty acids, and plays a crucial role in the regulation of oleic acid. In this study, 165 ten-week-old Cherry Valley ducks were used to investigate single nucleotide polymorphisms (SNPs) in the 5' regulatory region of the SCD1 gene, and their associations with duck serum biochemical levels and fatty acid composition. Two novel SNPs, g.936516 C > G and g.936551 T > C, were found by polymerase chain reaction-single-strand conformation polymorphism analysis and DNA sequencing methods, exhibiting six genotypes (AA, BB, CC, AB, AC, and BC). The frequency of the dominant genotype BB and allele B was 0.321 and 0.403, respectively. The polymorphism information content value was 0.617, indicating high polymorphism. The chi-square test indicated that the genotype distribution deviated markedly from Hardy-Weinberg equilibrium (P < 0.01). The linkage of the two mutant sites in the duck SCD1 gene had significant effects on the serum albumin, total protein, globulin, triglyceride, total cholesterol, and cholinesterase levels, as well as on 16 kinds of fatty acids except for C14:1 and C20:0 (P < 0.05). These results indicated that the C allele might have a positive effect on polyunsaturated fatty acids with potential health benefits. Therefore, the SCD1-gene-specific SNPs in the 5' regulatory region may be a useful marker for serum lipid, serum protein, and fatty acid composition in future marker-assisted selection for duck breeding.