MicroRNA miR‐2765‐3p regulates reproductive diapause by targeting FoxO in Galeruca daurica

Abstract

The forkhead box O (FoxO), as a conserved transcription factor, plays an indispensable role in regulating insect diapause. However, how FoxO is regulated to control diapause in insects remains unknown. In this study, we discovered functional binding sites for miR-2765-3p in the 3 untranslated region of FoxO in Galeruca daurica. The luciferase reporter assay showed that miR-2765-3p targeted FoxO and suppressed its expression. The expression profiles of miR-2765-3p and FoxO displayed opposite patterns during the female developmental process. Overexpression of miR-2765-3p by the injection of the miR-2765-3p agomir into adult females reduced FoxO expression, leading to the suppression of lipid accumulation, promotion of ovarian development, and inhibition of reproductive diapause. This is similar to the phenotype that results from the depletion of FoxO by injecting dsFoxO into adult females. In addition, the repression of miR-2765-3p by injecting the miR-2765-3p antagomir increased the FoxO transcript level, leading to the stimulation of lipid accumulation, depression of ovarian development, and induction of reproductive diapause. A hormone injection assay showed that the juvenile hormone (JH) agonist (methoprene) upregulated miR-2765-3p and downregulated FoxO. Notably, injecting methoprene rescued ovarian development defects associated with miR-2765-3p inhibition. These findings indicate that the JH/miR-2765-3p/FoxO axis plays a vital role in the regulation of reproductive diapause in G. daurica.

miR-2765 Modulates the Seasonal Polyphenism in Cacopsylla chinensis by Targeting a Novel Cold Rreceptor CcTRPC3

“…48,49 In Galeruca daurica, a specific miR-2765−3p regulates its target FoxO to mediate reproductive diapause. 50 This discovery extends our understanding of the miRNA and TRPC channels in modulating seasonal polyphenism.…”

“…In comparison to other regulator s , miRNA exhibits a distinct expression pattern by finely tuning its interactions with specific targets, thereby serving as a buffer to guarantee developmental adaptability . Various biological processes have revealed the feedback regulatory mechanisms between miRNAs and their target genes have been revealed in a wide range of biological processes. , In Galeruca daurica, a specific miR-2765–3p regulates its target FoxO to mediate reproductive diapause . This discovery extends our understanding of the miRNA and TRPC channels in modulating seasonal polyphenism.…”

Bmo‐miR‐6498‐5p suppresses Bombyx mori nucleopolyhedrovirus infection by down‐regulating BmPLPP2 to modulate pyridoxal phosphate content in B. mori

“…In most reports on identifying miRNA target genes in insects via dual luciferase assay, to eliminate the impact of the background, they tend to choose heterologous cells, such as HEK293T. For example, the dual luciferase assays to verify miR‐309a in Bactrocera dorsalis binds the transcription factor pannier (Zhang et al, 2022), novel_85 and novel_191 in Nilaparvata lugens bind to the CYP6ER1 and CarE1 coding regions (Mao et al, 2022), miR‐2765‐3p in Galeruca daurica binds to FoxO (Duan et al, 2022) were all conducted in HEK293T cells. Therefore, we performed dual luciferase assays in HEK293T cells to identify the interaction of miR‐6498‐5p and BmPLPP2 .…”

MicroR‐9c‐5p and novel‐mir50 co‐target Akt to regulate Lasioderma serricorne reproduction

“…In Galeruca daurica , JH inhibited the expression of FoxO by upregulating miR‐2765‐3p , which ultimately inhibited adult reproductive diapause (Duan et al. , 2022). Although the mechanisms by which 20E and JH regulate miRNAs in insects have been extensively studied, the manner in which insulin regulates miRNAs is unknown.…”

“…Similarly, 20E significantly induced the expression of B. dorsalis let-7 and miR-309a (Peng et al, 2019) and D. melanogaster let-7 cluster (miR-100/miR-125/let-7) (Chawla & Sokol, 2012), while D. melanogaster miR-8 (Jin et al, 2012) and B. mori miR-281 (Jiang et al, 2013) were significantly reduced. In Galeruca daurica, JH inhibited the expression of FoxO by upregulating miR-2765-3p, which ultimately inhibited adult reproductive diapause (Duan et al, 2022). Although the mechanisms by which 20E and JH regulate miRNAs in insects have been extensively studied, the manner in which insulin regulates miRNAs is unknown.…”