Whipworms of the genus Trichuris are nematode parasites that infect mammals and can lead to various intestinal diseases of human and veterinary interest. The most intimate interaction between the parasite and the host intestine occurs through the anterior region of the nematode body, inserted into the intestinal mucosa during infection. One of the most prominent structures of the nematode surface found at the infection site is the bacillary band, a surface domain formed by a number of cells, mostly stichocytes and bacillary glands, whose structure and function are still under debate. Here, we used confocal microscopy, field emission scanning electron microscopy, helium ion microscopy, transmission electron microscopy and FIB-SEM tomography to unveil the functional role of the bacillary gland cell. We analyzed the surface organization as well as the intracellular milieu of the bacillary glands of Trichuris muris in high pressure frozen/freeze-substituted samples. Results showed that the secretory content is preserved in all gland openings, presenting a projected pattern. FIB-SEM analysis showed that the lamellar zone within the bacillary gland chamber is formed by a set of lacunar structures that may exhibit secretory or absorptive functions. In addition, incubation of parasites with the fluid phase endocytosis marker sulforhodamine B showed a time-dependent uptake by the parasite mouth, followed by perfusion through different tissues with ultimate secretion through the bacillary gland. Taken together, the results show that the bacillary gland possess structural characteristics of secretory and absorptive cells and unequivocally demonstrate that the bacillary gland cell functions as a secretory structure.

鞭虫属鞭虫线虫是感染哺乳动物的线虫寄生虫，可导致人类和兽医感兴趣的各种肠道疾病。寄生虫和宿主肠道之间最密切的相互作用是通过线虫体的前部区域发生的，在感染期间插入肠粘膜。在感染部位发现的线虫表面最突出的结构之一是细菌带，这是由许多细胞形成的表面域，主要是缝合细胞和细菌腺，其结构和功能仍在争论中。在这里，我们使用共聚焦显微镜、场发射扫描电子显微镜、氦离子显微镜、透射电子显微镜和 FIB-SEM 断层扫描来揭示细菌腺细胞的功能作用。高压冷冻/冷冻替代样品中的鼠鞭毛虫。结果表明，所有腺体开口都保留了分泌物，呈现出投影模式。FIB-SEM 分析表明，细菌腺室内的层状区由一组可能具有分泌或吸收功能的腔隙结构形成。此外，寄生虫与液相内吞标记物磺基罗丹明 B 的孵育显示出寄生虫口腔的时间依赖性摄取，然后灌注通过不同的组织，最终通过杆菌腺分泌。综上所述，结果表明，杆菌腺具有分泌细胞和吸收细胞的结构特征，并明确表明，杆菌腺细胞具有分泌结构的功能。