Regulatory role of miRNAs during morphogenesis and cell specification in sea urchin early development

Abstract

Development of complex multi-cellular organisms requires careful regulation at the transcriptional as well as post-transcriptional levels. Post-transcriptional gene regulation is in part mediated by a class of 21-25 nucleotides long non-coding RNAs known as microRNAs (miRNAs). While we have made great progress in understanding the gene regulatory network of the early developmental events in the purple sea urchin, Strongylocentrotus purpuratus, not much is known about the posttranscriptional regulation mediated by miRNAs. miRNAs are essential for sea urchin gastrulation, a developmental stage where regulation of cell movement, cell proliferation, and cell specification need to be carefully controlled to ensure a successful embryo (Song et al. 2012). The current study tests the hypothesis that miRNAs regulate genes involved in cell migration and cell specification during early development. We took a candidate approach in examining potential genes important during gastrulation that may be targets of miRNA regulation. Results indicate that both cadherin and ß-catenin are translationally regulated by miRNAs. We identify miR-2007 and miRDeep 2-35240 to directly mediate the translational silencing of ß-catenin. Our results suggest that while the regulatory miRNAs of cadherin and ß-catenin may be different across species, the mechanism of their translational regulation by miRNAs is conserved.