Table_1_Identification of Odorant-Binding and Chemosensory Protein Genes in Mythimna separata Adult Brains Using Transcriptome Analyses.docx

Large numbers of chemosensory genes have been identified in the peripheral sensory organs of the pest Mythimna separata (Walker) to increase our understanding of chemoreception-related molecular mechanisms and to identify molecular targets for pest control. Chemosensory-related genes are expressed in various tissues, including non-sensory organs, and they play diverse roles. To better understand the functions of chemosensory-related genes in non-sensory organs, transcriptomic analyses of M. separata brains were performed. In total, 29 odorant-binding proteins (OBPs) and 16 chemosensory proteins (CSPs) putative genes were identified in the transcriptomic data set. The further examination of sex- and tissue-specific expression using RT-PCR suggested that eight OBPs (OBP5, -7, -11, -13, -16, -18, -21, and -24) and eight CSPs (CSP2–4, -8, CSP10–12, and -15) genes were expressed in the brain. Furthermore, bands representing most OBPs and CSPs could be detected in antennae, except for a few that underwent sex-biased expression in abdomens, legs, or wings. An RT-qPCR analysis of the expression profiles of six OBPs (OBP3–5, -9, -10, and -16) and two CSPs (CSP3 and CSP4) in different tissues and sexes indicated that OBP16 was highly expressed in male brain, and CSP3 and CSP4 were female-biased and highly expressed in brain. The expression levels of OBP5 and OBP10 in brain were not significantly different between the sexes. The findings expand our current understanding of the expression patterns of OBPs and CSPs in M. separata sensory and non-sensory tissues. These results provide valuable reference data for exploring novel functions of OBPs and CSPs in M. separata and may help in developing effective biological control strategies for managing this pest by exploring novel molecular targets.

科研人员已在害虫东方粘虫(Mythimna separata (Walker))的外周感觉器官中鉴定出大量化学感受基因(chemosensory genes)，以期加深对化学感受相关分子机制的理解，并筛选出害虫防治的潜在分子靶标。化学感受相关基因可在包括非感觉器官在内的多种组织中表达，并发挥多样的生物学功能。为进一步阐明化学感受相关基因在非感觉器官中的功能，本研究对东方粘虫的脑组织进行了转录组分析(transcriptomic analyses)。本转录组数据集中共鉴定出29个推定的气味结合蛋白(odorant-binding proteins, OBPs)基因以及16个推定的化学感受蛋白(chemosensory proteins, CSPs)基因。通过逆转录聚合酶链反应(RT-PCR)进一步检测基因的性别与组织表达特异性后发现，8个OBPs基因（OBP5、7、11、13、16、18、21和24）以及8个CSPs基因（CSP2~4、8、10~12和15）可在脑组织中表达。此外，除少数在腹部、足或翅膀中表现出性别偏向性表达(sex-biased expression)的基因外，绝大多数OBPs和CSPs的扩增条带均可在触角中被检测到。通过实时定量逆转录聚合酶链反应(RT-qPCR)分析6个OBPs基因（OBP3~5、9、10和16）以及2个CSPs基因（CSP3和CSP4）在不同组织和性别中的表达谱(expression profiles)后发现，OBP16在雄虫脑组织中高表达，而CSP3与CSP4则表现出雌性偏向性，且在脑组织中高表达。OBP5与OBP10在雌雄虫脑组织中的表达水平无显著差异。本研究结果拓展了学界对东方粘虫感觉与非感觉组织中OBPs和CSPs表达模式的认知，为探究OBPs与CSPs在东方粘虫中的新功能提供了宝贵的参考数据，同时也可为通过筛选新型分子靶标来开发高效害虫生物防治策略提供理论依据。