Center for Infectious Diseases, Heidelberg University Hospital, Heidelberg, Germany.
Institute for Theoretical Physics and BioQuant, Heidelberg University, Heidelberg, Germany.
Sci Adv. 2022 Apr;8(13):eabj5362. doi: 10.1126/sciadv.abj5362. Epub 2022 Mar 30.
Malaria-causing parasites proliferate within erythrocytes through schizogony, forming multinucleated stages before cellularization. Nuclear multiplication does not follow a strict geometric 2 progression, and each proliferative cycle produces a variable number of progeny. Here, by tracking nuclei and DNA replication, we show that individual nuclei replicate their DNA at different times, despite residing in a shared cytoplasm. Extrapolating from experimental data using mathematical modeling, we provide strong indication that a limiting factor exists, which slows down the nuclear multiplication rate. Consistent with this prediction, our data show that temporally overlapping DNA replication events were significantly slower than partially overlapping or nonoverlapping events. Our findings suggest the existence of evolutionary pressure that selects for asynchronous DNA replication, balancing available resources with rapid pathogen proliferation.
疟原虫在红细胞内通过裂殖生殖增殖,在细胞化之前形成多核阶段。核的增殖并不遵循严格的几何 2 级进展,每个增殖周期产生的后代数量是可变的。在这里,通过跟踪核和 DNA 复制,我们表明尽管位于共享细胞质中,但单个核在不同时间复制其 DNA。通过使用数学建模从实验数据推断,我们提供了强有力的证据表明存在一个限制因素,该因素减缓了核增殖率。与这一预测一致,我们的数据表明,时间上重叠的 DNA 复制事件明显比部分重叠或不重叠的事件慢。我们的研究结果表明,存在一种进化压力,它选择了异步 DNA 复制,在可用资源与快速病原体增殖之间取得平衡。