Shen Sifan, Zhang Long, Zhang Liwei
College of Grassland Science and Technology, China Agricultural University, Beijing 100193, China.
Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan 250100, China.
Insects. 2024 Jun 11;15(6):443. doi: 10.3390/insects15060443.
Insect development is intricately governed by hormonal signaling pathways, yet the pivotal upstream regulator that potentiates hormone activation remains largely elusive. The migratory locust, , exhibits population density-dependent phenotypic plasticity, encompassing traits such as flight capability, body coloration, and behavior. In this study, we elucidated a negative correlation between population density and ontogenetic development during the nymphal stage of locusts. We found that the level of density influences the developmental trajectory by modulating transcript abundance within the ecdysone signaling pathway, with knockdown of the prothoracicotropic hormone (PTTH) resulting in developmental delay. Transcriptomic analysis of locust brains across solitary and gregarious phases revealed significant differential expression of genes involved in various pathways, including protein synthesis, energy metabolism, hormonal regulation, and immunity. Notably, knockdown experiments targeting two energy regulators, adipokinetic hormone (AKH) and (), failed to elicit changes in the developmental process in solitary locusts. However, knockdown of () significantly shortened the developmental time in higher-density populations. Collectively, our findings underscore the regulatory role of population density in determining developmental duration and suggest that an immune-related gene contributes to the observed differences in developmental patterns.
昆虫的发育受到激素信号通路的复杂调控，然而，增强激素激活的关键上游调节因子在很大程度上仍不明确。飞蝗表现出种群密度依赖性的表型可塑性，包括飞行能力、体色和行为等特征。在本研究中，我们阐明了蝗虫若虫阶段种群密度与个体发育之间的负相关关系。我们发现密度水平通过调节蜕皮激素信号通路中的转录本丰度来影响发育轨迹，促前胸腺激素（PTTH）的敲低会导致发育延迟。对独居和群居阶段蝗虫大脑的转录组分析揭示了参与各种途径的基因存在显著差异表达，包括蛋白质合成、能量代谢、激素调节和免疫。值得注意的是，针对两种能量调节因子，即脂肪动激素（AKH）和（此处原文缺失具体因子）的敲低实验未能引起独居蝗虫发育过程的变化。然而，（此处原文缺失具体因子）的敲低显著缩短了高密度种群中的发育时间。总的来说，我们的研究结果强调了种群密度在决定发育持续时间方面的调节作用，并表明一个免疫相关基因促成了观察到的发育模式差异。
