MicroRNA miR‐285 modulates the metamorphosis in Galeruca daurica by targeting Br‐C

Abstract

AbstractBACKGROUNDGaleruca daurica has become a new pest on the Inner Mongolia grasslands since an abrupt outbreak in 2009 caused serious damage. As a pupa indicator during insect metamorphosis, the early response gene of the ecdysone signaling pathway, Broad‐Complex (Br‐C), plays a vital role in the growth and development of insects. MicroRNAs (miRNAs) are small non‐coding RNAs which mediate various biological activities, but it is unknown whether and how Br‐C is regulated by miRNAs.RESULTSTemporal expression profiles revealed that miR‐285 and Br‐C basically displayed an opposite trend during larval–adult development, and Br‐C was sharply up‐regulated on the last day of final‐instar larvae while miR‐285 was significantly down‐regulated. Both dual‐luciferase reporter assay and miRNA–mRNA interaction assay indicated that miR‐285 interacts with the coding sequence of Br‐C and represses its expression. Not only overexpression but also downexpression of miR‐285 led to the failure of larval to pupal to adult metamorphosis. In addition, both overexpression of miR‐285 and silence of Br‐C inhibited the expression of Br‐C and other ecdysone signaling pathway genes, including E74, E75, ECR, FTZ‐F1, and HR3. On the contrary, suppressing miR‐285 obtained opposite results. Further experiments showed that 20‐hydroxyecdysone down‐regulated miR‐285 and up‐regulated Br‐C and above‐mentioned genes, whereas juvenile hormone alalogue (JHA) resulted in opposite effects.CONCLUSIONOur results reveal that miR‐285 is involved in mediating the metamorphosis in G. daurica by targeting Br‐C in the ecdysone signaling pathway. miR‐285 and its target Br‐C could be as a potential target for G. daurica management. © 2024 Society of Chemical Industry.