Yaman Mustafa, Aydin Çiçek, Linde Andreas, Radek Renate
Department of Biology, Faculty of Arts and Science, Bolu Abant İzzet Baysal University, 14030 Bolu, Turkey.
Department of Biology, Faculty of Science, Karadeniz Technical University, 61080 Trabzon, Turkey.
Eur J Protistol. 2022 Oct;86:125913. doi: 10.1016/j.ejop.2022.125913. Epub 2022 Aug 24.
Gastrophysa viridula DeGeer 1775, the green dock leaf beetle, belongs to a group of beneficial insects, which can be used as a classical biological control agent against sorrels (Rumex sp., Polygonaceae). Therefore, any infection by pathogenic organisms in this beetle is undesirable. In the present study, a new microsporidian pathogen isolated from G. viridula was identified based on morphological and ultrastructural characteristics, supported with a molecular phylogenetic analysis. Light and transmission electron microscopy studies indicated that the microsporidium was polymorphic throughout its life cycle. Sporulation stages were not all in direct contact with the host-cell cytoplasm. The fresh single diplokaryotic spores of the secondary sporulation cycle had a long narrow morphology, measuring about 5 × 2.1 µm (n = 50). Octospores produced in the secondary sporulation cycle were also observed. Morphological and ultrastructural characteristics of the life cycle stages place it within the genus Vairimorpha. The phylogenetic tree constructed on the 16S rRNA gene sequence analysis supports the morphological and ultrastructural characteristics and indicates that the pathogen is closely related to the Vairimorpha clade of microsporidia. The pathogen is named Vairimorpha gastrophysae sp. nov.
1775年的绿码头叶甲（Gastrophysa viridula DeGeer）属于有益昆虫群体，可作为防治酸模（蓼科酸模属植物）的经典生物防治剂。因此，这种甲虫受到病原生物的任何感染都是不理想的。在本研究中，基于形态学和超微结构特征，并辅以分子系统发育分析，鉴定了一种从绿码头叶甲中分离出的新型微孢子虫病原体。光学显微镜和透射电子显微镜研究表明，该微孢子虫在其整个生命周期中具有多态性。孢子形成阶段并非都直接与宿主细胞的细胞质接触。二次孢子形成周期的新鲜单个双核孢子形态狭长，大小约为5×2.1微米（n = 50）。还观察到了二次孢子形成周期中产生的八孢子。生命周期各阶段的形态学和超微结构特征将其归入Vairimorpha属。基于16S rRNA基因序列分析构建的系统发育树支持形态学和超微结构特征，并表明该病原体与微孢子虫的Vairimorpha分支密切相关。该病原体被命名为新种Vairimorpha gastrophysae。
