Developmental growth is an intricate process involving the coordinated regulation of the expression of various genes, and microRNAs (miRNAs) play crucial roles in diverse processes throughout animal development. The ecdysone-responsive miRNA, miR-252, is normally upregulated during the pupal and adult stages of Drosophila development. Here, we found that overexpression of miR-252 in the larval fat body decreased total tissue mass through a reduction in both cell size and cell number, causing a concomitant decrease in larval size. Furthermore, miR-252 overexpression led to a delayed larval-to-pupal transition with defective anterior spiracle eversion, as well as a decrease in adult size and mass. Conversely, adult flies lacking miR-252 showed an increase in mass compared with control flies. We found that miR-252 directly targeted mbt, encoding a p21-activated kinase, to repress its expression. Notably, co-overexpression of mbt rescued the developmental and growth defects associated with miR-252 overexpression, indicating that mbt is a biologically relevant target of miR-252. Overall, our data support a role for the ecdysone/miR-252/mbt regulatory axis in growth control during Drosophila development.
Bibliographical noteFunding Information:
We thank the Bloomington Drosophila Stock Center for providing us with fly strains. We also thank T. Raabe (Universität Würzburg, Germany) and T. Neufeld (University of Minnesota, USA) for providing the anti-Mbt antibody and/or fly strains. This work was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2017R1D1A1B03035285 to Y.S.L.), and Korea University grants (to Y.S.L. and D.-H.L.). The authors declare no conflicts of interest.
© 2018 The Royal Entomological Society
ASJC Scopus subject areas
- Molecular Biology
- Insect Science