Department of Biology, University of Nevada Reno, Reno, NV, United States of America.
Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China.
PLoS Genet. 2019 Jul 29;15(7):e1007655. doi: 10.1371/journal.pgen.1007655. eCollection 2019 Jul.
Circadian clocks control the timing of animal behavioral and physiological rhythms. Fruit flies anticipate daily environmental changes and exhibit two peaks of locomotor activity around dawn and dusk. microRNAs are small non-coding RNAs that play important roles in post-transcriptional regulation. Here we identify Drosophila miR-210 as a critical regulator of circadian rhythms. Under light-dark conditions, flies lacking miR-210 (miR-210KO) exhibit a dramatic 2 hrs phase advance of evening anticipatory behavior. However, circadian rhythms and molecular pacemaker function are intact in miR-210KO flies under constant darkness. Furthermore, we identify that miR-210 determines the evening phase of activity through repression of the cell adhesion molecule Fasciclin 2 (Fas2). Ablation of the miR-210 binding site within the 3' UTR of Fas2 (Fas2ΔmiR-210) by CRISPR-Cas9 advances the evening phase as in miR-210KO. Indeed, miR-210 genetically interacts with Fas2. Moreover, Fas2 abundance is significantly increased in the optic lobe of miR-210KO. In addition, overexpression of Fas2 in the miR-210 expressing cells recapitulates the phase advance behavior phenotype of miR-210KO. Together, these results reveal a novel mechanism by which miR-210 regulates circadian locomotor behavior.
生物钟控制着动物行为和生理节律的时间安排。果蝇预测每日环境变化，并在黎明和黄昏左右表现出两次活动高峰。microRNAs 是小的非编码 RNA，在转录后调控中发挥重要作用。在这里，我们鉴定出果蝇 miR-210 是生物钟节律的关键调节因子。在光暗条件下，缺乏 miR-210 的果蝇（miR-210KO）表现出傍晚预期行为的显著 2 小时相位提前。然而，在持续黑暗下，miR-210KO 中的生物钟节律和分子节奏器功能保持完整。此外，我们发现 miR-210 通过抑制细胞粘附分子 Fasciclin 2（Fas2）来确定活动的傍晚相位。通过 CRISPR-Cas9 切除 Fas2 的 3'UTR 中的 miR-210 结合位点（Fas2ΔmiR-210）可使傍晚相位提前，与 miR-210KO 相似。实际上，miR-210 与 Fas2 存在遗传相互作用。此外，miR-210KO 中的 Fas2 丰度显著增加。此外，在表达 miR-210 的细胞中过表达 Fas2 可再现 miR-210KO 的相位提前行为表型。总之，这些结果揭示了 miR-210 调节生物钟运动行为的新机制。
