Sun Lili, Ma Heting, Gao Yuan, Wang Zhiying, Cao Chuanwang
Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, College of Forestry, Northeast Forestry University, Harbin, China.
Front Physiol. 2021 Oct 7;12:741362. doi: 10.3389/fphys.2021.741362. eCollection 2021.
Neuropeptides function as central neuromodulators and circulating hormones that modulate insect behavior and physiology. Leucokinin (LK) is an intercellular signaling molecule that mediates many physiological and behavioral processes. However, the functions of LK associated with environmental stress and feeding behavior in the fall webworm, , is little known. Our primary objective is to understand the function of LK and LK receptor (LKR) neuroendocrine system in . In the present study, the results showed that LK/LKR are expressed at different developmental stages and in various tissues of . A candidate receptor-ligand pairing for LK was identified in the larval transcriptome of . In a heterologous expression system, the calcium assay was used to demonstrate that LKR is activated by HcLKs in a dose-dependent manner, with 50% effective concentration (EC) values of 8.44-90.44nM. Knockdown of and by microinjecting target-specific dsRNA leads to several effects in , including feeding promotion, increase in resistance to desiccation and starvation stress, and regulation of water homeostasis. The transcript levels of (except in the knockdown group), , and increased, whereas those of , , and decreased; , (in the LK knockdown group), and gene expression was not influenced after and knockdown. Variations in mRNA expression levels in insulin-like peptide genes in the knockdown larvae suggest an essential role of these genes in survival in . To our knowledge, the present study is the first comprehensive study of LK and LKR - from gene to behavior - in .
神经肽作为中枢神经调质和循环激素，调节昆虫的行为和生理。亮氨酸激肽（LK）是一种介导许多生理和行为过程的细胞间信号分子。然而，关于落叶松毛虫中与环境应激和取食行为相关的亮氨酸激肽的功能却知之甚少。我们的主要目标是了解落叶松毛虫中亮氨酸激肽及其受体（LKR）神经内分泌系统的功能。在本研究中，结果表明亮氨酸激肽/亮氨酸激肽受体在落叶松毛虫的不同发育阶段和各种组织中均有表达。在落叶松毛虫幼虫转录组中鉴定出了亮氨酸激肽的一个候选受体 - 配体对。在异源表达系统中，采用钙测定法证明亮氨酸激肽受体可被落叶松毛虫亮氨酸激肽以剂量依赖方式激活，其50%有效浓度（EC）值为8.44 - 90.44 nM。通过显微注射靶标特异性双链RNA敲低落叶松毛虫的亮氨酸激肽和亮氨酸激肽受体基因会导致多种效应，包括促进取食、增强对干燥和饥饿胁迫的抗性以及调节水平衡。除亮氨酸激肽受体敲低组外，胰岛素样肽基因、海藻糖酶基因和水通道蛋白基因的转录水平升高，而己糖激酶基因、磷酸果糖激酶基因和丙酮酸激酶基因的转录水平降低；亮氨酸激肽敲低组中的海藻糖磷酸合酶基因和海藻糖酶基因以及亮氨酸激肽受体敲低组中的海藻糖磷酸合酶基因的表达在亮氨酸激肽和亮氨酸激肽受体敲低后未受影响。敲低幼虫中胰岛素样肽基因的mRNA表达水平变化表明这些基因在落叶松毛虫生存中起着重要作用。据我们所知，本研究是首次对落叶松毛虫中从基因到行为的亮氨酸激肽和亮氨酸激肽受体进行的全面研究。
