miR-71 and miR-263 Jointly Regulate Target Genes Chitin synthase and Chitinase to Control Locust Molting

PLoS Genet. 2016 Aug 17;12(8):e1006257. doi: 10.1371/journal.pgen.1006257. eCollection 2016 Aug.

Abstract

Chitin synthase and chitinase play crucial roles in chitin biosynthesis and degradation during insect molting. Silencing of Dicer-1 results in reduced levels of mature miRNAs and severely blocks molting in the migratory locust. However, the regulatory mechanism of miRNAs in the molting process of locusts has remained elusive. In this study, we found that in chitin metabolism, two crucial enzymes, chitin synthase (CHS) and chitinase (CHT) were regulated by miR-71 and miR-263 during nymph molting. The coding sequence of CHS1 and the 3'-untranslated region of CHT10 contain functional binding sites for miR-71 and miR-263, respectively. miR-71/miR-263 displayed cellular co-localization with their target genes in epidermal cells and directly interacted with CHS1 and CHT10 in the locust integument, respectively. Injections of miR-71 and miR-263 agomirs suppressed the expression of CHS1 and CHT10, which consequently altered chitin production of new and old cuticles and resulted in a molting-defective phenotype in locusts. Unexpectedly, reduced expression of miR-71 and miR-263 increased CHS1 and CHT10 mRNA expression and led to molting defects similar to those induced by miRNA delivery. This study reveals a novel function and balancing modulation pattern of two miRNAs in chitin biosynthesis and degradation, and it provides insight into the underlying molecular mechanisms of the molting process in locusts.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Chitin / biosynthesis*
  • Chitin Synthase / biosynthesis
  • Chitin Synthase / genetics*
  • Chitinases / biosynthesis
  • Chitinases / genetics*
  • Gene Expression Regulation, Enzymologic
  • Grasshoppers / enzymology
  • Grasshoppers / genetics
  • MicroRNAs / biosynthesis
  • MicroRNAs / genetics*
  • Molting / genetics
  • Phylogeny
  • Proteolysis
  • RNA Interference

Substances

  • MicroRNAs
  • Chitin
  • Chitin Synthase
  • Chitinases

Grants and funding

This work was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB11010000), National Basic Research Program of China (2012CB114102) and National Natural Science Foundation of China Grants (31472051, 31301915, 31430023, 31272380). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.