Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands.
Department of Microbiology and Immunology, Center for Molecular Parasitology, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, USA.
J Cell Biol. 2024 Dec 2;223(12). doi: 10.1083/jcb.202406064. Epub 2024 Nov 1.
The malaria-causing parasite, P. falciparum, replicates through schizogony, a tightly orchestrated process where numerous daughter parasites are formed simultaneously. Proper division and segregation of one-per-cell organelles, like the mitochondrion and apicoplast, are essential, yet remain poorly understood. We developed a new reporter parasite line that allows visualization of the mitochondrion in blood and mosquito stages. Using high-resolution 3D imaging, we found that the mitochondrion orients in a cartwheel structure, prior to stepwise, non-geometric division during last-stage schizogony. Analysis of focused ion beam scanning electron microscopy data confirmed these mitochondrial division stages. Furthermore, these data allowed us to elucidate apicoplast division steps, highlighted its close association with the mitochondrion, and showed putative roles of the centriolar plaques in apicoplast segregation. These observations form the foundation for a new detailed mechanistic model of mitochondrial and apicoplast division and segregation during P. falciparum schizogony and pave the way for future studies into the proteins and protein complexes involved in organelle division and segregation.
疟原虫，引起疟疾的寄生虫，通过裂殖生殖进行复制，这是一个紧密协调的过程，在此过程中会同时形成许多子寄生虫。适当的细胞分裂和细胞器（如线粒体和顶体）的分离是必不可少的，但仍知之甚少。我们开发了一种新的报告寄生虫系，可用于可视化血液和蚊子阶段的线粒体。使用高分辨率 3D 成像，我们发现线粒体在分阶段裂殖生殖的最后阶段之前，会先以车轮状结构定向排列。对聚焦离子束扫描电子显微镜数据的分析证实了这些线粒体分裂阶段。此外，这些数据还使我们能够阐明顶体的分裂步骤，突出了它与线粒体的密切关联，并显示了中心粒斑在顶体分离中的可能作用。这些观察结果为疟原虫裂殖生殖过程中线粒体和顶体分裂和分离的新详细机制模型奠定了基础，并为未来研究参与细胞器分裂和分离的蛋白质和蛋白质复合物铺平了道路。
