Two novel intronic polymorphisms of bovine FGF21 gene are associated with body weight at 18 months in Chinese cattle

Fibroblast growth factor 21 (FGF21) is a hepatic hormone that regulates peripheral glucose tolerance, energy balance and lipid metabolism. Prior evidence suggests that FGF21 may have the potential to favorably reduce obesity. The objective of the present study was to identify single nucleotide polymorphisms (SNPs) of bovine FGF21 using 1255 animals representing the five main Chinese breeds and to investigate the effect of these SNPs on economic traits in Nanyang cattle. Four significant SNPs were identified, one was a synonymous mutation and the other three were in intronic regions. The polymorphism information content (PIC) analysis showed that four beef cattle populations (NY, JX, LX and QC) had a moderate genetic diversity at the four loci while the beef and dairy population (CRS) had a low level. Additionally, allele and genotype frequencies for the beef breeds were significantly different from CRS, implying that these mutations are possibly associated with some quantitative traits. Moreover, linkage disequilibrium analysis and haplotype frequencies were also reported. Seven different haplotypes were identified and haplotype TCCC was predominant in all five cattle breeds. Association analysis suggested that SNPs g.297C>G and g.940C>T of bovine FGF21 were associated with higher body weight at 18 months within NY cattle, which would contribute to cattle breeding and genetics through marker-assisted selection (MAS).