MiR-277 Drives Sexually Dimorphic Development in Ericerus pela Through Differential Regulation of Dlg1 and Lar

Insects exhibit diverse developmental strategies, yet the molecular basis of sexual dimorphism in metamorphosis remains largely elusive. The white wax scale insect Ericerus pela (hereafter, WWS) displays extreme sexual dimorphism: females undergo paurometamorphosis (four stages), while males undergo hyperpaurometamorphosis (five stages). Although miR-277 is highly expressed in both sexes, its functional role in this process was unknown. Here, we demonstrate that miR-277 drives sexually dimorphic development through differential regulation of two distinct targets. Combining gain- and loss-of-function assays, dual-luciferase reporter assays, and RNA interference, we show that miR-277 suppresses Discs large 1 (Dlg1) in females, disrupting cellular signaling and causing growth retardation and morphological abnormalities. In males, miR-277 inhibits tyrosine-protein phosphatase Lar (Lar), a receptor tyrosine phosphatase linked to nervous system development; knockdown of Lar severely impairs male metamorphosis but does not affect females. These findings reveal a previously unrecognized, sex-specific miRNA regulatory switch: miR-277 concurrently modulates a cell-growth pathway in females and a neurodevelopmental pathway in males, thereby generating divergent developmental outcomes. Our study provides the mechanistic insight into miRNA-mediated sexual dimorphism in insects and advances the understanding of how post-transcriptional regulators shape metamorphic diversity.