Department of Chemistry and Biochemistry, Université de Moncton, 18 Antonine-Maillet Avenue, Moncton, New Brunswick, E1A 3E9, Canada.
Fredericton Research and Development Centre, Agriculture and Agri-Food Canada, 850 Lincoln Road, Fredericton, New Brunswick, E3B 4Z7, Canada.
J Insect Sci. 2022 Jan 1;22(1). doi: 10.1093/jisesa/ieac004.
The Colorado potato beetle (Leptinotarsa decemlineata (Say)) is an insect that can adapt to various challenges, including temperature fluctuations or select insecticide treatments. This pest is also an ongoing threat to the potato industry. Small noncoding RNAs such as miRNAs, which can control posttranscriptionally the expression of various genes, and piRNAs, which can notably impact mRNA turnover, are modulated in insects under different conditions. Unfortunately, information regarding the expression status of key players involved in their synthesis and function is for the most part lacking. The current study thus aims at assessing the levels of such targets in L. decemlineata exposed to hot and cold temperatures as well as treated to the insecticides chlorantraniliprole, clothianidin, imidacloprid, and spinosad. Transcript expression levels of Ago1, Ago2, Ago3, Dcr2a, Dcr2b, Expo-5, Siwi-1, and Siwi-2, components of pathways associated with small noncoding RNA production or function, were measured by qRT-PCR and revealed modulation of select transcripts in response to temperature challenges and to select insecticides. RNAi-mediated reduction of Ago2 transcript levels in L. decemlineata injected with Ago2-targeting dsRNA and exposed to cold and warm temperatures was also conducted. Changes in survival rates were observed for the latter condition in dsRNA- versus saline-injected insects. These results showcase the differential expression of select targets involved in small noncoding RNA homeostasis and provide leads for the subsequent assessment of their involvement during stress response in L. decemlineata using RNAi-based approaches.
科罗拉多马铃薯甲虫（Leptinotarsa decemlineata（Say））是一种能够适应各种挑战的昆虫，包括温度波动或选择杀虫剂处理。这种害虫也是马铃薯产业的持续威胁。小非编码 RNA，如 miRNA，可以在后转录水平上控制各种基因的表达，而 piRNA 可以显著影响 mRNA 的周转，在不同条件下的昆虫中被调节。不幸的是，关于参与其合成和功能的关键因子表达状态的信息在很大程度上仍然缺乏。因此，本研究旨在评估 L. decemlineata 在暴露于高温和低温以及用杀虫剂氯虫腈、噻虫嗪、吡虫啉和多杀菌素处理时这些靶标的水平。通过 qRT-PCR 测量了与小非编码 RNA 产生或功能相关途径的 Ago1、Ago2、Ago3、Dcr2a、Dcr2b、Expo-5、Siwi-1 和 Siwi-2 等成分的转录表达水平，并揭示了对温度挑战和选择杀虫剂的响应中选择转录本的调节。还进行了用 Ago2 靶向 dsRNA 注射 L. decemlineata 并暴露于冷温和温暖温度下降低 Ago2 转录本水平的 RNAi 介导。在 dsRNA-与盐水注射昆虫相比，后一种情况下观察到存活率的变化。这些结果展示了参与小非编码 RNA 动态平衡的选定靶标的差异表达，并为随后使用基于 RNAi 的方法评估它们在 L. decemlineata 应激反应中的参与提供了线索。
