Dong Wan-Ying, Wang Bing, Wang Gui-Rong
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China.
Front Neuroanat. 2021 Dec 16;15:791900. doi: 10.3389/fnana.2021.791900. eCollection 2021.
The olfactory sensing system of the syrphid fly is essential in pollination and prey localization, but little is known about the ultrastructural organization of their olfactory organs. In this study, the morphology, distribution, and ultrastructural organization of antennal sensilla of in both sexes were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Neuronal responses of a subtype of sensilla basiconica to floral scent compounds were recorded by single sensillum recording (SSR). Ten morphological types, including Böhm bristles, sensilla chaetica, microtrichiae, sensilla trichodea, sensilla basiconica, sensilla clavate, sensilla coeloconica, sensilla styloconica, sensilla placodea, and sensory pit, were identified. Except for Böhm bristles and sensilla chaetica, which were distributed on the scape and pedicel of antennae, innervated sensilla were densely distributed on the flagellum, a vital sensory organ. Further, observing ultrastructural organization showed that the sensilla trichodea, basiconica, and clavate are single-walled with multiple nanoscale pores perforating the cuticle. Sensilla coeloconica are double-walled and have no wall pores, but instead, have longitudinal grooves along with the pegs. Sensilla chaetica, Böhm bristles, and microtrichiae did not have wall pores on the cuticle or sensory cells at the base. The SSR results indicated that neuron B housed in the subtype of sensilla basiconica I (SBI) mainly responded to methyl eugenol and other aromatic compounds. Overall, our results provide valuable information to understand the morphology and ultrastructure of antennal sensilla from . These findings are beneficial for the studies of the neuronal function map of olfactory sensilla and for determining evolutionary relationships in Diptera.
食蚜蝇的嗅觉传感系统在授粉和猎物定位中至关重要，但对其嗅觉器官的超微结构组织了解甚少。在本研究中，通过扫描电子显微镜（SEM）和透射电子显微镜（TEM）观察了两性触角感器的形态、分布和超微结构组织。通过单感器记录（SSR）记录了锥形感器亚型对花香化合物的神经元反应。鉴定出十种形态类型，包括博氏鬃毛、毛形感器、微毛、刚毛状感器、锥形感器、棒形感器、腔锥形感器、栓锥形感器、板形感器和感觉窝。除了分布在触角柄节和梗节上的博氏鬃毛和毛形感器外，有神经支配的感器密集分布在鞭节上，鞭节是一个重要的感觉器官。此外，超微结构观察表明，刚毛状感器、锥形感器和棒形感器是单壁的，角质层上有多个纳米级小孔。腔锥形感器是双壁的，没有壁孔，而是有纵向凹槽和栓。毛形感器、博氏鬃毛和微毛在角质层上没有壁孔，基部也没有感觉细胞。SSR结果表明，锥形感器I型（SBI）亚型中的神经元B主要对甲基丁香酚和其他芳香化合物有反应。总体而言，我们的结果为了解食蚜蝇触角感器的形态和超微结构提供了有价值的信息。这些发现有助于嗅觉感器神经元功能图谱的研究以及确定双翅目的进化关系。
