Identifying Novel SNPs and Allelic Sequences of the Stearoyl-CoA Desaturase Gene (SCD) in Fat-Tailed and Thin-Tailed Sheep Breeds

Abstract

Stearoyl-coenzyme A-desaturase (SCD) is a candidate gene for genetic variation in the fatty acid composition of meat and milk. The SCD enzyme catalyzes a D9-cis desaturation of a number of fatty acyl-CoA substrates with a preference for C16:0 and C18:0, which are converted to C16:1 and C18:1, respectively (Enoch et al. 1976). SCD is also a key enzyme in endogenous production of the cis-9, trans-11 isomer of conjugated linoleic acid (CLA) (Bauman et al. 1999). In sheep, two single nucleotide polymorphisms (SNPs), located in intron 4 (Miari et al. 2009) and intron 2 (GarciaFernandez et al. 2010), displayed significant association with CLA/VA variability and milk fat percentage, respectively. The objective of this study was to determine the existence of polymorphisms in the SCD gene in 458 lambs belonging to three traditional fat-tailed, medium fat-tailed, and thin-tailed Iranian sheep breeds.