State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400715, China; CSIRO Food Futures Flagship, Canberra, ACT, 2601, Australia; CSIRO Ecosystem Sciences, Canberra, ACT, 2601, Australia.
Agricultural Sciences, Murdoch University, Murdoch, WA, 6150, Australia.
Insect Biochem Mol Biol. 2020 Mar;118:103313. doi: 10.1016/j.ibmb.2020.103313. Epub 2020 Jan 3.
Sensory neuron membrane proteins (SNMPs) play a critical role in the insect olfactory system but there is a deficit of functional studies beyond Drosophila. Here, we use a combination of available genome sequences, manual curation, genome and transcriptome data, phylogenetics, expression profiling and gene knockdown to investigate SNMP superfamily in various insect species with a focus on Lepidoptera. We curated 81 genes from 36 insect species and identified a novel lepidopteran SNMP gene family, SNMP3. Phylogenetic analysis shows that lepidopteran SNMP3, but not the previously annotated lepidopteran SNMP2, is the true homologue of the dipteran SNMP2. Digital expression, microarray and qPCR analyses show that the lepidopteran SNMP1 is specifically expressed in adult antennae. SNMP2 is widely expressed in multiple tissues while SNMP3 is specifically expressed in the larval midgut. Microarray analysis suggest SNMP3 may be involved in the silkworm immunity response to virus and bacterial infections. We functionally characterized SNMP1 in the silkworm using RNA interference (RNAi) and behavioral assays. Our results suggested that Bombyx mori SNMP1 is a functional orthologue of the Drosophila melanogaster SNMP1 and plays a critical role in pheromone detection. Split-ubiquitin yeast hybridization study shows that BmorSNMP1 has a protein-protein interaction with the pheromone receptor (BmorOR1), and the co-receptor (BmorOrco). Concluding, we propose a novel molecular model in which BmorOrco, BmorSNMP1 and BmorOR1 form a heteromer in the detection of the silkworm sex pheromone bombykol.
感觉神经元膜蛋白（SNMPs）在昆虫嗅觉系统中起着至关重要的作用，但除了果蝇之外，对其功能的研究还很缺乏。在这里，我们使用现有的基因组序列、手动注释、基因组和转录组数据、系统发育学、表达谱分析和基因敲低等方法，对各种昆虫物种中的 SNMP 超家族进行了研究，重点是鳞翅目昆虫。我们从 36 种昆虫物种中注释了 81 个基因，并鉴定了一个新的鳞翅目 SNMP 基因家族，即 SNMP3。系统发育分析表明，鳞翅目 SNMP3，而不是之前注释的鳞翅目 SNMP2，是双翅目 SNMP2 的真正同源物。数字表达、微阵列和 qPCR 分析表明，鳞翅目 SNMP1 特异性表达于成虫触角。SNMP2 在多种组织中广泛表达，而 SNMP3 特异性表达于幼虫中肠。微阵列分析表明，SNMP3 可能参与了家蚕对病毒和细菌感染的免疫反应。我们使用 RNA 干扰（RNAi）和行为测定法对家蚕中的 SNMP1 进行了功能表征。我们的结果表明，家蚕 SNMP1 是果蝇 SNMP1 的功能同源物，在家蚕信息素检测中起着关键作用。分裂泛素酵母杂交研究表明，BmorSNMP1 与性信息素受体（BmorOR1）和共受体（BmorOrco）存在蛋白-蛋白相互作用。综上所述，我们提出了一个新的分子模型，即 BmorOrco、BmorSNMP1 和 BmorOR1 在家蚕性信息素 bombykol 的检测中形成异源二聚体。
