Zebrafish MiR-430 Promotes Deadenylation and Clearance of Maternal mRNAs

TLDR

MicroRNAs represent a small fraction of vertebrate genes and their in vivo roles are largely unknown, but zebrafish miR‑430 is expressed at the onset of zygotic transcription and regulates early developmental morphogenesis. The authors used a microarray and in vivo target validation to demonstrate that miR‑430 directly regulates hundreds of mRNAs. The study shows that miR‑430 targets hundreds of maternally expressed mRNAs, accelerating their deadenylation and clearance during early embryogenesis.

Abstract

MicroRNAs (miRNAs) comprise 1 to 3% of all vertebrate genes, but their in vivo functions and mechanisms of action remain largely unknown. Zebrafish miR-430 is expressed at the onset of zygotic transcription and regulates morphogenesis during early development. By using a microarray approach and in vivo target validation, we find that miR-430 directly regulates several hundred target messenger RNA molecules (mRNAs). Most targets are maternally expressed mRNAs that accumulate in the absence of miR-430. We also show that miR-430 accelerates the deadenylation of target mRNAs. These results suggest that miR-430 facilitates the deadenylation and clearance of maternal mRNAs during early embryogenesis.