Inter-cellular variation in DNA content of Entamoeba histolytica originates from temporal and spatial uncoupling of cytokinesis from the nuclear cycle.
Inter-cellular variation in DNA content of Entamoeba histolytica originates from temporal and spatial uncoupling of cytokinesis from the nuclear cycle.
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DOI：
10.1371/journal.pntd.0000409
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发表时间：
2009
影响因子：
3.8
通讯作者：
Lohia A
中科院分区：
文献类型：
--
作者：
Mukherjee C;Majumder S;Lohia A
以前在溶组织内阿米巴原虫中发现了基因组在单个细胞核和单个细胞中多个细胞核的积累，这导致了这种单细胞真核生物的遗传异质性。在这项研究中，我们证明了这种遗传异质性是这种生物细胞周期的固有特征。染色体分离发生在多种新型微管组件上，包括多极纺锤体。溶组织芽胞杆菌的细胞质分裂是通过机械切断细胞质桥来完成的，要么独立完成，要么在邻近细胞的帮助下完成。重要的是，细胞质分裂在时间和空间上都与核分裂周期不耦合，导致不平等子细胞的形成。整倍体和多倍体细胞的分选表明，这些亚群在进一步生长时获得了不同的DNA含量。我们的研究最终表明，遗传异质性源于该原生生物独特的细胞分裂事件模式。增殖的真核细胞非常精确地调节它们的DNA合成、染色体分离和细胞分裂，以便子细胞在遗传上是相同的。我们的研究表明，在原生病原体溶组织内阿米巴的增殖细胞中，经常观察到DNA的重复复制，然后在非典型和不同的微管结构上分离。在这种寄生虫中，细胞分裂是不稳定的，因此每个子细胞可能包含一个或多个细胞核，有时没有细胞核。这种细胞周期事件的解耦和DNA含量不相等的子细胞的存活导致了溶组织芽孢杆菌的遗传异质性。我们的研究强调了内阿米巴原虫基因组固有的可塑性，以及这种原生生物在缺乏严格调控机制的情况下生存的能力，这是真核细胞周期的一个标志。
Accumulation of multiple copies of the genome in a single nucleus and several nuclei in a single cell has previously been noted in Entamoeba histolytica, contributing to the genetic heterogeneity of this unicellular eukaryote. In this study, we demonstrate that this genetic heterogeneity is an inherent feature of the cell cycle of this organism. Chromosome segregation occurs on a variety of novel microtubular assemblies including multi-polar spindles. Cytokinesis in E. histolytica is completed by the mechanical severing of a thin cytoplasmic bridge, either independently or with the help of neighboring cells. Importantly, cytokinesis is uncoupled from the nuclear division cycle, both temporally and spatially, leading to the formation of unequal daughter cells. Sorting of euploid and polyploid cells showed that each of these sub-populations acquired heterogeneous DNA content upon further growth. Our study conclusively demonstrates that genetic heterogeneity originates from the unique mode of cell division events in this protist. Proliferating eukaryotic cells regulate their DNA synthesis, chromosome segregation, and cell division with great precision so that daughter cells are genetically identical. Our study demonstrates that in proliferating cells of the protist pathogen Entamoeba histolytica re-duplication of DNA followed by segregation on atypical and diverse microtubular structures is frequently observed. In this parasite, cell division is erratic, so that each daughter cell may contain one or more nuclei and sometimes no nuclei. This uncoupling of cell cycle events and survival of daughter cells with unequal DNA contents leads to genetic heterogeneity in E. histolytica. Our study highlights the inherent plasticity of the Entamoeba genome and the ability of this protist to survive in the absence of strict regulatory mechanisms that are a hallmark of the eukaryotic cell cycle.
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影响因子：
3.4
作者：
Dastidar, Promita Ghosh;Lohia, Anuradha
通讯作者：
Lohia, Anuradha
影响因子：
9.4
作者：
Ghosh, S;Frisardi, M;Samuelson, J
通讯作者：
Samuelson, J
影响因子：
64.8
作者：
Biron, D;Libros, P;Moses, E
通讯作者：
Moses, E
DOI：
10.1098/rstb.1995.0117
发表时间：
1995-09-29
期刊：
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY OF LONDON SERIES B-BIOLOGICAL SCIENCES
影响因子：
--
作者：
MITCHISON, TJ
通讯作者：
MITCHISON, TJ
影响因子：
2.1
作者：
SOLIS, FJ;BARRIOS, R
通讯作者：
BARRIOS, R