We describe new insights into the morphology and life history of the bizarre parasite Haplozoon axiothellae (Dinoflagellata) using light microscopy (LM), scanning electron microscopy (SEM), and confocal laser scanning microscopy (CLSM). Trophonts were isolated from the intestines of host maldanid polychaetes, Axiothella rubrocincta, collected from San Juan Island, Washington, USA. LM and SEM confirmed features previously observed, such as amphiesmal projections, mature and immature junctions between the nucleated compartments of the vermiform syncytium and visible polygonal alveoli. CLSM of adult trophonts fluorescently stained for DNA, tubulin, centrin, and plasma membrane demonstrated several new ultrastructural traits: (1) an extensive basket of parallel microtubules within the trophomere used for host attachment, (2) two physically separated MTOCs (i.e. putative pairs of basal bodies) beneath pores on the ventral side of each compartment, (3) robust mitotic and/or meiotic spindles associated with one to four nuclei in each compartment, (4) spindles with polar bodies that are disconnected from the MTOCs, (5) a centrin-stained fibril within the trophomeres that potentially functions to retract the motile stylet, and (6) cytokinesis in the posterior-most compartments. This study renames haplozoan compartments using the suffix “-mere” rather than “-cyte” (i.e. trophomere, gonomere, sporomere) to reflect their status within a single syncytium.

中文翻译：

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使用共聚焦激光扫描显微镜深入了解单倍体寄生虫（甲鞭毛藻）的形态

我们使用光学显微镜 (LM)、扫描电子显微镜 (SEM) 和共聚焦激光扫描显微镜 (CLSM)描述了对奇异寄生虫Haplozoon axiothellae (Dinoflagellata)的形态和生活史的新见解。Trophonts 从宿主 Maldanid polychaetes, Axiothella rubrocincta的肠道中分离出来，收集自美国华盛顿州圣胡安岛。LM 和 SEM 确认了先前观察到的特征，例如两性突起、蠕虫合胞体的有核隔室和可见的多边形肺泡之间的成熟和未成熟连接。对 DNA、微管蛋白、中心蛋白和质膜进行荧光染色的成体滋养体的 CLSM 证明了几个新的超微结构特征：（1）滋养体内用于宿主附着的大量平行微管篮子，（2）两个物理分离的 MTOC（即假定的对基体）在每个隔室腹侧的孔下，（3）与每个隔室中一到四个核相关的强大有丝分裂和/或减数分裂纺锤体，（4）具有与 MTOC 断开的极体的纺锤体，(5) 滋养球内的中心蛋白染色的原纤维，它可能具有收回运动管心针的功能，以及 (6) 最后部隔室中的胞质分裂。这项研究使用后缀“-mere”而不是“-cyte”（即滋养体、生殖体、孢子体）重命名单倍体隔室，以反映它们在单个合胞体中的状态。