Search

Recent studies suggest that microRNA (miRNA) plays important roles in the control of immune response and tolerance. We previously found that the expression level of antimicrobial peptide gene Drosomycin (Drs) is decreased in miR-964 overexpressing flies. Here, we further verified that miR-964 deficiency leads to hyper-activation of Drs. In addition, we employed three widely-used bioinformatic algorithms to screen potential miR-964 targets. Finally, we identified that miR-964 modulates Toll signaling pathway, at least in part, by repressing the expression of Drs. Taken together, our study identifies miR-964 as a modulator of Toll signaling and enriches the repertoire of immune-modulating miRNAs in Drosophila., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Drosophila have served as a model for research on innate immunity for decades. However, knowledge of the post-transcriptional regulation of immune gene expression by microRNAs (miRNAs) remains rudimentary. In the present study, using small RNA-seq and bioinformatics analysis, we identified 67 differentially expressed miRNAs in Drosophila infected with Escherichia coli compared to injured flies at three time-points. Furthermore, we found that 21 of these miRNAs were potentially involved in the regulation of Imd pathway-related genes. Strikingly, based on UAS-miRNAs line screening and Dual-luciferase assay, we identified that miR-9a and miR-981 could both negatively regulate Drosophila antibacterial defenses and decrease the level of the antibacterial peptide, Diptericin. Taken together, these data support the involvement of miRNAs in the regulation of the Drosophila Imd pathway., (Copyright © 2017 Elsevier Ltd. All rights reserved.)