The miR-7-5p/Ci Regulates Fat Differentiation and Energy Metabolism Reprogramming in Spodoptera frugiperda.

The invasive pest Spodoptera frugiperda threatens global agriculture. Understanding its growth regulation is key for developing novel control strategies. This study reveals that the transcription factor Cubitus interruptus (SfCi) of S. frugiperda, an unstable nuclear protein with conserved C2H2 zinc finger domains, is directly targeted and negatively regulated by miR-7-5p. Knocking down Sfci via RNA interference induces metabolic reprogramming: it promotes triglyceride storage by enhancing adipocyte differentiation while inhibiting lipolysis, and simultaneously increases glucose utilization to fuel larval development. Molecularly, this shift upregulates adipogenesis genes and suppresses cell proliferation genes. These findings establish the miR-7-5p/Ci regulatory module as a core regulator balancing lipid and glucose metabolism to coordinate energy allocation and development in S. frugiperda.