Goose FMO3 gene cloning, tissue expression profiling, polymorphism detection and association analysis with trimethylamine level in the egg yolk

摘要

Abstract Flavin-containing monooxygenase 3 (FMO3) plays a critical role in catalyzing the conversion of trimethylamine (TMA) to trimethylamine- N -oxide (TMAO) in vivo . Despite the well-documented association between FMO3 mutations and a ‘fishy’ off-flavor eggs in chicken and quail, little information is available regarding the molecular characteristic of goose ( Anser cygnoides ) FMO3 and its relationship with the yolk TMA content. To fill these gaps, we cloned the full-length cDNA sequence of goose FMO3 , which comprised 1851bp encoding 531 amino acids. FMO3 mRNA was dramatically expressed in liver than in other tissues in the geese. Eight single nucleotide polymorphisms (SNPs) were detected in the entire coding region. The CC genotype at the T669C site, GG at the A723G site, and AA at the G734A site of FMO3 were highly significantly associated with elevated TMA content in goose egg yolk ( P P =0.0429, OR=4.1300, 95%CI=1.0390–16.4270, and P =0.0251, OR=4.6060, 95%CI=1.1620–18.2620, respectively). This work lays a foundation for studying the function of FMO3 and yolk TMA content in goose. However, studies using larger sample sizes and more goose breeds are required to determine whether the fishy off-flavor trait exists in goose. Highlights ? The full cDNA of goose FMO3 was cloned for the first time. ? T669C, A723G, and G734A of goose FMO3 were associated with elevated TMA content of egg yolk. ? Significant difference in allele distribution was found in G734A and T885C between choline-vulnerable and choline-tolerant individuals.