Mechanism Of MicroRNA-133Mediated Phase Change In The Migratory Locust

Phenotypic plasticity is ubiquitous and primarily controlled by underlying interactions between environmental factors and genetic factors, in which the function of microRNA (miRNA) remains unknown. The migratory locust, a worldwide pest species, displays pronounced phenotypic plasticity termed population density-dependent phase transition between gregarious and solitary phase. Previous studies have demonstrated that the genes involved in dopamine synthesis and release regulate the phase transition of locusts and that miRNAs exhibited different expression profiles between the gregarious and solitary phases.In this study, we report a miRNA, miR-133, which participates in dopamine production and behavior transition by negatively regulating two critical genes henna and pale, in the dopamine pathway of the locusts. By In situ hybridization and immunohistochemical analyses, we demonstrated that miR-133expression in the protocerebrum was negatively correlated with henna and pale expression.To confirm the interaction between miR-133and henna/pale in vitro, we performed luciferase reporter assays and found that miR-133can interact with henna/pale. Furthermore, miR-133regulated henna mRNA stability by binding its coding region and controled pale mRNA translation by binding its3’untranslated region.Moreover, miR-133overexpression suppressed henna and pale expression, which decreased dopamine production and caused the locust behavior to shift from gregarious to solitary phase. Conversely, inhibition of miR-133increased henna and pale expression, which resulted in gregarious-like behavior in the solitary locusts. This study reveals a novel functional role and modulation pattern of miRNA in the phenotypic plasticity and provides insights to explore the underlying molecular mechanisms of locusts phase transition.