The Key Laboratory for Silviculture and Conservation of the Ministry of Education, School of Forestry, Beijing Forestry University, 35 Qinghua Dong Road, Haidian District, Beijing, 100083, People's Republic of China.
Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, 151 Malianwa North Road, Haidian District, Beijing, 100193, People's Republic of China.
BMC Genomics. 2022 Jun 22;23(1):461. doi: 10.1186/s12864-022-08655-w.
Insect olfactory proteins can transmit chemical signals in the environment that serve as the basis for foraging, mate searching, predator avoidance and oviposition selection. Semanotus bifasciatus is an important destructive borer pest, but its olfactory mechanism is not clear. We identified the chemosensory genes of S. bifasciatus in China, then we conducted a phylogenetic analysis of the olfactory genes of S. bifasciatus and other species. And the expression profiles of odorant binding proteins (OBPs) genes in different tissues and different genders of S. bifasciatus were determined by quantitative real-time PCR for the first time.
A total of 32 OBPs, 8 chemosensory proteins (CSPs), 71 odorant receptors (ORs), 34 gustatory receptors (GRs), 18 ionotropic receptors (IRs), and 3 sensory neuron membrane proteins (SNMPs) were identified. In the tissue expression analysis of OBP genes, 7 OBPs were higher expressed in antennae, among them, SbifOBP2, SbifOBP3, SbifOBP6, SbifOBP7 and SbifOBP20 were female-biased expression, while SbifOBP1 was male-biased expression and SbifOBP22 was no-biased expression in antennae. In addition, the expressed levels of SbifOBP4, SbifOBP12, SbifOBP15, SbifOBP27 and SbifOBP29 were very poor in the antennae, and SbifOBP4 and SbifOBP29 was abundant in the head or legs, and both of them were male-biased expression. While SbifOBP15 was highly expressed only at the end of the abdomen with its expression level in females three times than males. Other OBPs were expressed not only in antennae but also in various tissues.
We identified 166 olfactory genes from S. bifasciatus, and classified these genes into groups and predicted their functions by phylogenetic analysis. The majority of OBPs were antenna-biased expressed, which are involved in odor recognition, sex pheromone detection, and/or host plant volatile detection. However, also some OBPs were detected biased expression in the head, legs or end of the abdomen, indicating that they may function in the different physiological processes in S. bifasciatus.
昆虫嗅觉蛋白可以传递环境中的化学信号，这些信号是觅食、交配搜索、避免捕食者和产卵选择的基础。桑天牛是一种重要的破坏性蛀虫，但它的嗅觉机制尚不清楚。我们在中国鉴定了桑天牛的化学感觉基因，然后对桑天牛和其他物种的嗅觉基因进行了系统发育分析。并首次通过定量实时 PCR 确定了桑天牛不同组织和不同性别的气味结合蛋白 (OBP) 基因的表达谱。
共鉴定出 32 个嗅觉结合蛋白、8 个化学感觉蛋白、71 个气味受体、34 个味觉受体、18 个离子型受体和 3 个感觉神经元膜蛋白。在 OBP 基因的组织表达分析中，7 个 OBP 在触角中表达较高，其中 SbifOBP2、SbifOBP3、SbifOBP6、SbifOBP7 和 SbifOBP20 表现为雌性偏表达，而 SbifOBP1 为雄性偏表达，SbifOBP22 则在触角中无偏表达。此外，SbifOBP4、SbifOBP12、SbifOBP15、SbifOBP27 和 SbifOBP29 在触角中的表达水平非常差，SbifOBP4 和 SbifOBP29 在头部或腿部丰富，均表现为雄性偏表达。而 SbifOBP15 仅在腹部末端高度表达，其在雌性中的表达水平是雄性的三倍。其他 OBP 不仅在触角中表达，而且在各种组织中表达。
我们从桑天牛中鉴定出 166 个嗅觉基因，并通过系统发育分析将这些基因分为不同的组，并预测其功能。大多数 OBP 表现出触角偏表达，它们参与气味识别、性信息素检测和/或寄主挥发物检测。然而，也有一些 OBP 被检测到在头部、腿部或腹部末端表现出偏表达，表明它们可能在桑天牛的不同生理过程中发挥作用。
