Preliminary Evaluation Of MiR-219 Expression Pattern And Its Function

MicroRNAs (miRNAs) are important post-transcriptional modulators of gene expression, which have been implicated in many physiological and pathological processes. In this study, we analyzed the miR-219 spatial and temporal expression profile in zebrafish, rat and monkey using Northern blotting and whole mounts ISH technologies. In the brains of rhesus monkeys and rats, miR-219 expression showed in the brain-specifc and aged-ralated manner. In zebrafish, miR-219 mainly express in mid-, hindbrain and spinal cord from 16s stages, and reached peak expression at 2dpf. We firstly found the detailed spatial and temporal expression in the spinal cord. Moreover, knockdown and overexpression of miR-219 led to specific embryonic defects, especially the defects of overexpression phenocopied ntl gene mutant or knockdown: reduced tail and abnormal somites. This phenotype characterized the dose response in the injection of pre-miR-219. Furthermore, TUNEL assay showed that overexpression of miR-219 induced significant cell apoptosis. Moreover, we found overexpression of miR-219 led to cell apoptosis in the primary culture of rat cortical neurons. Lastly, we screened some possible target genes of miR-219 by a computational algorithm and found numb is a direct target of miR-219. Our preliminary data suggested that miR-219 potentially play an important role in the regulation network of embryonic development.