Association between fatty acid compositions and genotypes of FABP4 and LXR-alpha in Japanese Black cattle

BACKGROUND: Fatty acid composition has become an important trait in the beef industry in terms of beef flavor and decreasing the circulating concentration of LDL cholesterol. In this study, we examined the association between polymorphisms of six genes, adipocytes-type fatty acid binding protein (FABP4), liver X receptor α (LXRα), cytochrome b(5 )(Cyt b(5)), long-chain acyl-CoA synthetase (ACSL) 1, ACSL4 and diacylglycerol acyltransferase 2 (DGAT2) and fatty acid composition. RESULTS: Sequence comparisons revealed 14 single nucleotide polymorphisms in six genes. Four of them, I74V and V110M in FABP4 and G51E and V133I in LXRα, were nonsynonymous substitutions. The associations between the genotypes and fatty acid compositions were analyzed by using 234 Japanese Black cattle. The genotypes of FABP4 I74V and LXRα V133I were significantly associated with palmitoleic acids (C16:1, P = 0.0086) and linoleic acid (C18:2, P = 0.0121) content in intramuscular fat, respectively. CONCLUSION: Our findings suggest that the two polymorphisms of FABP4 I74V and LXRα V133I might be genetic factors in part associated with palmitoleic acid (FABP4 I74V) and linoleic acid (LXRα V133I) composition in intramuscular fat of Japanese Black cattle, respectively. Especially, FABP4 I74V had highly significant effect (P < 0.01) on C16:1 proportion, indicating that the I/I homozygote exhibited 0.5% higher percentage than V/V homozygote.