1. Downregulation of the Host Gene jigr1 by miR-92 Is Essential for Neuroblast Self-Renewal in Drosophila.
- Author
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Yuva-Aydemir Y, Xu XL, Aydemir O, Gascon E, Sayin S, Zhou W, Hong Y, and Gao FB
- Subjects
- 3' Untranslated Regions, Animals, Brain embryology, Brain metabolism, DNA-Binding Proteins genetics, Drosophila Proteins genetics, Gene Expression Regulation, Developmental, Larva genetics, Larva metabolism, Male, MicroRNAs genetics, Neural Stem Cells metabolism, Neuroglia cytology, Neuroglia metabolism, RNA, Messenger genetics, RNA, Messenger metabolism, Sequence Alignment, DNA-Binding Proteins metabolism, Down-Regulation, Drosophila genetics, Drosophila Proteins metabolism, MicroRNAs metabolism, Neural Stem Cells cytology
- Abstract
Intragenic microRNAs (miRNAs), located mostly in the introns of protein-coding genes, are often co-expressed with their host mRNAs. However, their functional interaction in development is largely unknown. Here we show that in Drosophila, miR-92a and miR-92b are embedded in the intron and 3'UTR of jigr1, respectively, and co-expressed with some jigr1 isoforms. miR-92a and miR-92b are highly expressed in neuroblasts of larval brain where Jigr1 expression is low. Genetic deletion of both miR-92a and miR-92b demonstrates an essential cell-autonomous role for these miRNAs in maintaining neuroblast self-renewal through inhibiting premature differentiation. We also show that miR-92a and miR-92b directly target jigr1 in vivo and that some phenotypes due to the absence of these miRNAs are partially rescued by reducing the level of jigr1. These results reveal a novel function of the miR-92 family in Drosophila neuroblasts and provide another example that local negative feedback regulation of host genes by intragenic miRNAs is essential for animal development.
- Published
- 2015
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