Polymorphisms of Fatty Acid Synthase Gene and their Association with Milk Production Traits in Chinese Holstein Cows.

The multifunctional enzyme fatty acid synthase (FASN) catalyzed the second step of the de novo biosynthesis of long-chain fatty acids in mammals. In this research, we investigated the variants in ketoacyl reductase (KR) and thioesterase (TE) domains in FASN by using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP). As a result, two single nucleotide polymorphisms (SNPs) were detected and genotyped in 407 Chinese Holstein cows. The non-synonymous g.16024G>A, g.17924G>A in KR and TE domains respectively resulted in a non-conservative substitution of alanine by threonine. g.17924G>A was associated with milk fat percentage, and the milk fat percentage of homozygous genotype AA was significantly higher than the other genotypes. The polymorphism information content (PIC) analysis showed that g.17924G>A in the cows population belonged to the intermediate polymorphism level. The results preliminarily indicated that g.17924 G>A of FASN gene is a potential genetic marker for application of marker-assisted selection programmers to improve milk fat percentage in Chinese dairy cattle. [ABSTRACT FROM AUTHOR]