Multiple miRNAs jointly regulate the biosynthesis of ecdysteroid in the holometabolous insects, Chilo suppressalis
- 1Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, China
- 2Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
- 3Institute of Plant Protection, Jiangxi Academy of Agricultural Science, Nanchang 330200, China
- 4College of Life Sciences and Resource Environment, Yichun University, Yichun 336000, China
- Corresponding author: lifei18{at}zju.edu.cn
-
↵5These authors contributed equally to this work.
Abstract
The accurate rise and fall of active hormones is important for insect development. The ecdysteroids must be cleared in a timely manner. However, the mechanism of suppressing the ecdysteroid biosynthesis at the right time remains unclear. Here, we sequenced a small RNA library of Chilo suppressalis and identified 300 miRNAs in this notorious rice insect pest. Microarray analysis yielded 54 differentially expressed miRNAs during metamorphosis development. Target prediction and in vitro dual-luciferase assays confirmed that seven miRNAs (two conserved and five novel miRNAs) jointly targeted three Halloween genes in the ecdysteroid biosynthesis pathway. Overexpression of these seven miRNAs reduced the titer of 20-hydroxyecdysone (20E), induced mortality, and retarded development, which could be rescued by treatment with 20E. Comparative analysis indicated that the miRNA regulation of metamorphosis development is a conserved process but that the miRNAs involved are highly divergent. In all, we present evidence that both conserved and lineage-specific miRNAs have crucial roles in regulating development in insects by controlling ecdysteroid biosynthesis, which is important for ensuring developmental convergence and evolutionary diversity.
Keywords
Footnotes
-
Article is online at http://www.rnajournal.org/cgi/doi/10.1261/rna.061408.117.
-
Freely available online through the RNA Open Access option.
- Received March 20, 2017.
- Accepted August 18, 2017.
This article, published in RNA, is available under a Creative Commons License (Attribution 4.0 International), as described at http://creativecommons.org/licenses/by/4.0/.
