MicroRNA-14 as an efficient suppressor to switch off ecdysone production after ecdysis in insects. Issue 9 (2nd September 2019)

• Record Type: Journal Article
• Authors: He, Kang; Xiao, Huamei; Sun, Yang; Situ, Gongming; Xi, Yu; Li, Fei
• Is Part Of: RNA biology. Volume 16:Issue 9(2019)
• Page Start: 1313
• Page End: 1325
• Publication Date: 2019-09-02
• Subjects: Microrna -- molting timing -- developmental synchrony -- ecdysone; RNA -- Periodicals; Molecular biology -- Periodicals; Molecular biology; RNA; Periodicals; 572.8805
• DOI: 10.1080/15476286.2019.1629768
• Languages: English
• ISSNs: 1547-6286

Abstract

ABSTRACT: The precise increase and decrease of hormone ecdysone are critical for accurate development in insects. Most previous works focus on transcriptional activation of ecdysone production; however, little is known about the mechanism of switching off ecdysone biosynthesis after ecdysis. Here, we showed that the precursor microRNA-14 (pre-miR-14) encodes two mature miRNAs in silkworm; both of these two mature miRNAs regulate various genes in the ecdysone-signalling pathway. Bmo-miR-14-5p targets on nine genes whereas Bmo-miR-14-3p targets on two genes in the same pathway. These two mature miRNAs increased immediately after the ecdysis, efficiently suppressing the 20-hydroxyecdysone (20E) biosynthesis, the upstream regulation, and the downstream response genes. Knocking down either of two mature miRNAs or both of them delays moult development, impairing development synchrony in antagomir-treated groups. In addition, overexpressing Bmo-miR-14-5p but not Bmo-miR-14-3p significantly affected the 20E titer and increased the moulting time variation, suggesting that Bmo-miR-14-5p, though it is less abundant, has more potent effects in development regulation than Bmo-miR-14-3p . In summary, we present evidence that a pre-miRNA encodes two mature miRNAs targeting on the same pathway, which significantly improves miRNA regulation efficiencies to programmatically switch off ecdysone biosynthesis.