RESUMEN
Polymorphisms in miRNA genes could potentially alter various biological processes by influencing the processing and (or) target selection of miRNAs. The rs14120863 (C > G) mutation, which we characterized in a Gushi-Anka F2 resource population, resides in the precursor region of miR-1666. Association analysis with chicken carcass and growth traits showed that the SNP was significantly associated with carcass weight, evisceration weight, breast muscle weight, leg muscle weight, and body weight at 8 weeks of age, as well as some body size indexes including shank girth, chest breadth, breast bone length, and body slanting length, in the Gushi-Anka F2 resource population. Quantitative RT-PCR results showed that miR-1666 expression levels in muscle tissues differed within various genotypes. Experiment in DF1 cells further confirmed that the SNP in miR-1666 could significantly alter mature miRNA production. Subsequently, using dual-luciferase report assay, we verified that miR-1666 could perform its function through targeting of the CBFB gene. In conclusion, the SNP in the precursor of miR-1666 could significantly reduce mature miR-1666 production. It may further affect the function of miR-1666 through the target gene CBFB, hence it is associated with chicken growth traits.