Regulation Of Circadian Rhythm And Sleep By Mir-375-Timeless Interaction In Drosophila

MicroRNAs are important coordinators of circadian regulation that mediate the fine-tuning of gene expression. Although many studies have shown the effects of individual miRNAs on the circadian clock, the global functional miRNA-mRNA interaction network involved in the circadian system remains poorly understood. Here, we used CLEAR (Covalent Ligation of Endogenous Argonaute-bound RNAs)-CLIP (Cross-Linking and Immuno-Precipitation) to explore the regulatory functions of miRNAs in the circadian system by comparing the miRNA-mRNA interactions betweenDrosophilawild-type strainW(1118)and a mutant of the key circadian transcriptional regulator Clock (Clk(jrk)). This experimental approach unambiguously identified tens of thousands of miRNA-mRNA interactions in both the head and body. The miRNA-mRNA interactome showed dramatic changes in theClk(jrk)flies. Particularly, among similar to 300 miRNA-mRNA circadian relevant interactions, multiple interactions involving core clock genespdp1,tim,andvridisplayed distinct changes as a result of theClkmutation. Based on the CLEAR-CLIP analysis, we found a novel regulation of the circadian rhythm and sleep by themiR-375-timelessinteraction. The results indicated thatClkdisruption abolished normal rhythmic expression ofmiR-375and the functional regulation occurred in the l-LNv neurons, wheremiR-375modulated the circadian rhythm and sleep via targetingtimeless. This work provides the first global view of miRNA regulation in the circadian rhythm.