Proliferation of Plasmodium falciparum in red blood cells is the cause of malaria and is underpinned by an unconventional cell division mode, called schizogony. Contrary to model organisms, P. falciparum 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 P. falciparum, 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.

中文翻译：

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疟疾寄生虫中，扩展的无 DNA 核内区室组织中心体微管。


恶性疟原虫在红细胞中的增殖是疟疾的病因，其基础是一种非常规的细胞分裂模式，称为分裂。与模式生物相反，恶性疟原虫通过不被胞质分裂中断的多轮核分裂进行复制。关键核分裂因素的组织和动态仍然知之甚少。中心粒斑，即恶性疟原虫的中心体，作为微管组织中心，具有无中心粒、无定形结构。寄生虫细胞核的尺寸较小，无法通过经典荧光显微镜对核内微管组织进行详细分析。我们应用最近开发的超分辨率和延时成像协议来描述分裂过程中的微管重新配置。对中心蛋白、核孔和微管定位的分析揭示了中心粒斑块的两个不同的区室。虽然中心蛋白是核外的，但我们通过相关光和电子断层扫描证实，微管在以前未知的扩展核内区室中成核，该区室缺乏染色质但蛋白质密集。这项研究为非常规中心体生成了一个工作模型，使人们能够更好地了解真核细胞分裂的多样性。