Muzzi Maurizio, Mancini Emiliano, Fratini Emiliano, Cervelli Manuela, Gasperi Tecla, Mariottini Paolo, Persichini Tiziana, Bologna Marco Alberto, Di Giulio Andrea
Department of Science, University Roma Tre, 00146 Rome, Italy.
Laboratorio Interdipartimentale di Microscopia Elettronica (LIME), University Roma Tre, 00146 Rome, Italy.
Insects. 2022 Jan 26;13(2):132. doi: 10.3390/insects13020132.
Members of the family Meloidae are known to produce cantharidin, a highly toxic monoterpene found in their hemolymph and exuded as droplets capable of deterring many predators. As a nuptial gift, males transfer large amounts of cantharidin to females via a spermatophore, which is formed by specific accessory glands containing high concentrations of this terpene. Using light, electron and ion beam microscopy, the ultrastructural features of the three pairs of male accessory glands as well as the glandular part of the were comparatively investigated in seven species of blister beetles belonging to five different tribes and two subfamilies. All gland pairs examined share common features such as mesodermal derivation, the presence of muscle sheath, a developed rough endoplasmic reticulum, abundant mitochondria, secretory vesicles, and microvillated apical membranes. Within the same species, glands exhibit distinctive features, suggesting that each pair is responsible for the formation of a specific substance. The , while showing many similarities within the family, often exhibit features unique to each of the individual species investigated, whereas the accessory glands of the first and second pairs display the highest degree of ultrastructural variability. A comparison across the species shows an interesting constancy limited to ultrastructural features in the third pair of accessory glands. The similarities and differences among the species are discussed in the light of the available literature and in relation to the potential role that blister beetles' male accessory glands could play in the storage and management of cantharidin.
芫菁科昆虫已知会产生斑蝥素，这是一种剧毒的单萜类化合物，存在于它们的血淋巴中，并以液滴形式分泌出来，能够威慑许多捕食者。作为一种求偶礼物，雄性通过精包将大量斑蝥素传递给雌性，精包由含有高浓度这种萜类化合物的特定附属腺形成。利用光学显微镜、电子显微镜和离子束显微镜，对属于五个不同族和两个亚科的七种芫菁科甲虫的三对雄性附属腺以及 的腺体部分的超微结构特征进行了比较研究。所有检查的腺体对都有共同特征，如中胚层起源、存在肌肉鞘、发达的粗面内质网、丰富的线粒体、分泌小泡和微绒毛化的顶端膜。在同一物种内，腺体表现出独特的特征，表明每一对腺体都负责形成一种特定的物质。 虽然在科内显示出许多相似之处，但通常表现出所研究的每个个体物种特有的特征，而第一对和第二对附属腺表现出最高程度的超微结构变异性。跨物种比较显示，第三对附属腺的超微结构特征存在有趣的恒定性。根据现有文献，并结合芫菁科甲虫雄性附属腺在斑蝥素储存和管理中可能发挥的潜在作用，讨论了物种之间的异同。
