Centre for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany.
Electron Microscopy Core Facility, Heidelberg University, Heidelberg, Germany.
Life Sci Alliance. 2021 Sep 17;4(11). doi: 10.26508/lsa.202101199. Print 2021 Nov.
Proliferation of in red blood cells is the cause of malaria and is underpinned by an unconventional cell division mode, called schizogony. Contrary to model organisms, replicates by multiple rounds of nuclear divisions that are not interrupted by cytokinesis. Organization and dynamics of critical nuclear division factors remain poorly understood. Centriolar plaques, the centrosomes of , serve as microtubule organizing centers and have an acentriolar, amorphous structure. The small size of parasite nuclei has precluded detailed analysis of intranuclear microtubule organization by classical fluorescence microscopy. We apply recently developed super-resolution and time-lapse imaging protocols to describe microtubule reconfiguration during schizogony. Analysis of centrin, nuclear pore, and microtubule positioning reveals two distinct compartments of the centriolar plaque. Whereas centrin is extranuclear, we confirm by correlative light and electron tomography that microtubules are nucleated in a previously unknown and extended intranuclear compartment, which is devoid of chromatin but protein-dense. This study generates a working model for an unconventional centrosome and enables a better understanding about the diversity of eukaryotic cell division.
疟原虫在红细胞中的增殖是疟疾的病因，它依赖于一种非常规的细胞分裂模式，称为裂殖生殖。与模式生物不同，疟原虫通过多次核分裂而不是胞质分裂进行复制。关键核分裂因子的组织和动态仍知之甚少。中心粒斑， 的中心体，充当微管组织中心，具有无中心体的、无定形的结构。寄生虫核的小尺寸使得通过经典荧光显微镜对核内微管组织进行详细分析变得困难。我们应用最近开发的超分辨率和延时成像方案来描述裂殖生殖过程中的微管重排。对中心体蛋白、核孔和微管定位的分析揭示了中心粒斑的两个不同区域。虽然中心体蛋白位于核外，但我们通过共聚焦和电子断层扫描关联确认，微管是在一个以前未知的、扩展的核内区域中被引发的，该区域不含染色质，但富含蛋白质。这项研究为一种非常规的中心体生成了一个工作模型，并使我们更好地理解了真核细胞分裂的多样性。
