Liu Weimin, Yang Xiuli, Wang Yuxin, Zhang Jianzhen, Zhao Xiaoming
Shanxi Key Laboratory of Nucleic Acid Biopesticides, Institute of Applied Biology, Shanxi University, Shanxi, China.
Shanxi Key Laboratory of Nucleic Acid Biopesticides, Institute of Applied Biology, Shanxi University, Shanxi, China; College of Life Science, Shanxi University, Shanxi, China.
Pestic Biochem Physiol. 2025 Nov;214:106598. doi: 10.1016/j.pestbp.2025.106598. Epub 2025 Jul 24.
The four-and-a-half LIM domain protein 2 (FHL2) is a conserved transcriptional co-regulator critical for vertebrate development and metabolism, yet its roles in arthropods remain poorly understood. Here, we report the functional characterization of LmFHL2 in the migratory locust Locusta migratoria, a devastating pest reliant on precise molting cycles for growth and swarming. Phylogenetic and expression analyses revealed high conservation of LmFHL2 across insects, with predominant expression in integument and gut tissues. Temporal expression profiling showed that LmFHL2 was primarily expressed during the adult developmental stage. Notably, topical application of juvenile hormone analogue (JHA) to adult locusts resulted in significant upregulation of LmFHL2 expression levels. RNAi-mediated silencing of LmFHL2 resulted in developmental defects in L. migratoria, including molting-associated mortality, reduced body weight, and impaired wing morphogenesis. Histopathological examination showed delayed cuticle formation and disorganized fat body architecture, while integrated multi-omics analyses identified multiple differentially expressed genes and metabolites associated with amino acid, lipid, and carbohydrate metabolism. Mechanistically, knockdown of LmFHL2 disrupted core metabolic pathways-serine hydroxymethyltransferase (SHMT), phosphoenolpyruvate carboxykinase (PCK), and purine nucleoside phosphorylase (PNP), etc.-leading to significant reductions in amino acid, triglycerides, and glycogen content. These findings establish LmFHL2 as a critical regulator of cuticular remodeling and energy-related core metabolic processes during the nymph-to-adult molting transition, providing potential molecular target for pest management strategies.
四又二分之一LIM结构域蛋白2（FHL2）是一种保守的转录共调节因子，对脊椎动物的发育和代谢至关重要，但其在节肢动物中的作用仍知之甚少。在此，我们报告了飞蝗（Locusta migratoria）中LmFHL2的功能特征，飞蝗是一种具有毁灭性的害虫，其生长和群体行为依赖于精确的蜕皮周期。系统发育和表达分析表明，LmFHL2在昆虫中具有高度保守性，主要在体壁和肠道组织中表达。时间表达谱分析显示，LmFHL2主要在成虫发育阶段表达。值得注意的是，对成年蝗虫局部施用保幼激素类似物（JHA）会导致LmFHL2表达水平显著上调。RNA干扰介导的LmFHL2沉默导致飞蝗出现发育缺陷，包括与蜕皮相关的死亡增加、体重减轻和翅形态发生受损。组织病理学检查显示表皮形成延迟和脂肪体结构紊乱，而综合多组学分析确定了多个与氨基酸、脂质和碳水化合物代谢相关的差异表达基因和代谢物。从机制上讲，LmFHL2的敲低破坏了核心代谢途径——丝氨酸羟甲基转移酶（SHMT）、磷酸烯醇式丙酮酸羧激酶（PCK）和嘌呤核苷磷酸化酶（PNP）等——导致氨基酸、甘油三酯和糖原含量显著降低。这些发现表明LmFHL2是若虫到成虫蜕皮转变过程中表皮重塑和能量相关核心代谢过程的关键调节因子，为害虫管理策略提供了潜在的分子靶点。
