Coccidian parasites possess complex life cycles involving asexual proliferation followed by sexual development leading to the production of oocysts. Coccidian oocysts are persistent stages which are secreted by the feces and transmitted from host to host guaranteeing life cycle progression and disease transmission. The robust bilayered oocyst wall is formed from the contents of two organelles, the wall-forming bodies type I and II (WFBI, WFBII), located exclusively in the macrogametocyte. Eimeria nieschulzi has been used as a model parasite to study and follow gametocyte and oocyst development. In this study, the gametocyte and oocyst wall formation of E. nieschulzi was analyzed by electron microscopy and immuno-histology. A monoclonal antibody raised against the macrogametocytes of E. nieschulzi identified a tyrosine-rich glycoprotein (EnGAM82) located in WFBII. Correlative light and electron microscopy was used to examine the vesicle-specific localization and spatial distribution of GAM82-proteins during macrogametocyte maturation by this monoclonal antibody. In early and mid-stages, the GAM82-protein is ubiquitously distributed in WFBII. Few hours later, the protein is arranged in subvesicular structures. It was possible to show that the substructure of WFBII and the spatial distribution of GAM82-proteins probably represent pre-synthesized cross-linked materials prior to the inner oocyst wall formation. Dityrosine-cross-linked gametocyte proteins can also be confirmed and visualized by fluorescence microscopy (UV light, autofluorescence of WFBII).

球虫寄生虫具有复杂的生命周期，涉及无性繁殖，然后发生性发育，导致卵囊的产生。球虫卵囊是持续的阶段，由粪便分泌并在宿主之间传播，从而保证生命周期的进展和疾病的传播。坚固的双层卵囊壁由两个细胞器的内容物形成，它们分别位于巨配子体细胞中，类型为I和II型壁形成体（WFBI，WFBII）。Eimeria nieschulzi已被用作模型寄生虫来研究和跟踪配子细胞和卵囊的发育。在这项研究中，通过电子显微镜和免疫组织学分析了尼氏肠杆菌的配子细胞和卵囊壁的形成。单克隆抗体，针对巨噬细胞nieschulzi大肠杆菌鉴定出位于WFBII中的富含酪氨​​酸的糖蛋白（EnGAM82）。使用相关的光镜和电子显微镜检查该单克隆抗体在巨配子细胞成熟过程中GAM82蛋白的囊泡特异性定位和空间分布。在早期和中期，GAM82蛋白普遍分布在WFBII中。几个小时后，该蛋白质排列在囊泡下。可能显示出WFBII的亚结构和GAM82蛋白的空间分布可能代表了卵囊内壁形成之前的预合成交联材料。也可以通过荧光显微镜（紫外光，WFBII的自发荧光）来确认和观察二酪氨酸交联的配子细胞蛋白。