Abstract：Polymorphisms in microRNAs (miRNAs) genes can potentially alter various biological processes by influencing the processing and/or target selection of miRNAs. To investigate if the single rs16057773 (A＞G) mutation, which we characterized resides in the terminal loop of pre-miR-1816, could affect its processing and had a biological function, association study of the polymorphisms with chicken (Gallus) carcass and growth traits using the Gushi-Anka F2 resource population showed that this SNP was significantly associated with birth weight and postnatal weight till 12 weeks as well as some body size indexes including shank girth, body slanting length, crista breadth (P＜0.05). Moreover, the SNP was significantly associated with carcass weight (P＜0.05). The result of association study suggested that the SNP in the precursor of miR-1816 played an important role in the growth of chicken. Mfold predicted that the SNP had no effect on miRNA secondary structure. Through constructing miR-1816 pcDNA3.1-EGFP expression vectors of 2 genotypes and transfecting DF1 cells subsequently, quantitative Real-time PCR (qRT-PCR) results showed that there was no significant difference between different genotype and mature miR-1816 expression level. The result indicated that this SNP in the precursor of miR-1816 could not alter the processing of miR-1816. This study revealed that the SNP in the miR-1816 was significantly associated with chicken economic performance. However, this SNP in the terminal loop of pre-miR-1816, which did not alter the stability of miR-1816 secondary structure, had no effect on miRNA processing. This study suggested that there was a different path that mediated the function of miRNA SNP, and will contribute to the study of miRNA processing.
