MicroRNA-140-5p impairs zebrafish embryonic bone development via targeting BMP-2.

MicroRNA-140-5p (miRNA-140-5p) is important for embryonic bone development. In this study, we found that miRNA-140-5p and its binding site in the 3'UTR of bone morphogenetic protein 2 (BMP-2) are highly conserved among vertebrates, and miRNA-140-5p negatively regulates both zebrafish and human BMP-2 genes. Microinjection of miRNA-140-5p or BMP-2b morpholino into zebrafish embryos led to a similar phenotype, including shortened tails, curved trunks, and defects in cranial cartilage. Moreover, miRNA-140-5p injection induced zebrafish embryo malformation that could be significantly rescued by microinjection of BMP-2 mRNA. In conclusion, our results indicated that miRNA-140-5p regulates zebrafish embryonic bone development via targeting BMP-2.