Abstract：
Olfaction plays indispensable roles in insect behavior such as host location, foraging, oviposition, and avoiding predators. Chemosensory proteins (CSPs) can discriminate the hydrophobic odorants and transfer them to the odorant receptors. Presently, CSPs have been identified in many insect species. However, their presence and functions remain unknown in Bactrocera dorsalis, a destructive and invasive insect pest in the fruit and vegetable industry. Here, we annotated eight CSP genes in the genome of B. dorsalis. The results of quantitative real-time polymerase chain reaction (RT-qPCR) showed that BdorCSP3 was highly expressed in the antennae. Molecular docking and in vitro binding assays showed that BdorCSP3 had a good binding ability to host volatiles methyl eugenol (ME, male-specific attractant) and β-caryophyllene (potential female attractant). Subsequently, CRISPR/Cas9 was used to generate BdorCSP3-/- mutants. Electroantennograms (EAGs) and behavioral assays revealed that male mutants significantly reduced the preference for ME, while female mutants lost their oviposition preference to β-caryophyllene. Our data indicated that BdorCSP3 played important roles in the perception of ME and β-caryophyllene. The results not only expanded our knowledge of the olfaction perception mechanism of insect CSPs but also provided a potential molecular target for the control of B. dorsalis.
摘要：
嗅觉在昆虫行为中起着不可或缺的作用，如寄主位置，觅食,产卵,避免捕食者。化学感觉蛋白（CSP）可以区分疏水性气味物质并将其转移到气味受体。目前,已经在许多昆虫物种中鉴定了CSP。然而,它们的存在和功能在背实杆菌中仍然未知，水果和蔬菜行业的破坏性和入侵性害虫。这里,我们在背芽孢杆菌基因组中注释了8个CSP基因。定量实时聚合酶链反应（RT-qPCR）结果表明，BdorCSP3在触角中高表达。分子对接和体外结合实验表明，BdorCSP3对宿主挥发物甲基丁香酚具有良好的结合能力（ME，雄性特异性引诱剂）和β-石竹烯（潜在的雌性引诱剂）。随后，CRISPR/Cas9用于产生BdorCSP3-/-突变体。电天线图（EAG）和行为测定表明，雄性突变体显着降低了对ME的偏好，而雌性突变体失去了对β-石竹烯的产卵偏好。我们的数据表明BdorCSP3在ME和β-石竹烯的感知中起重要作用。该结果不仅扩展了我们对昆虫CSP的嗅觉感知机制的认识，而且为控制背芽孢杆菌提供了潜在的分子靶标。
