Inter-cellular variation in DNA content of Entamoeba histolytica originates from temporal and spatial uncoupling of cytokinesis from the nuclear cycle.

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 inher...

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Bibliographic Details
Published in:PLoS Neglected Tropical Diseases
Main Authors: Chandrama Mukherjee, Shubhra Majumder, Anuradha Lohia
Format: Article in Journal/Newspaper
Language:English
Published: Public Library of Science (PLoS) 2009
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Online Access:https://doi.org/10.1371/journal.pntd.0000409
https://doaj.org/article/a62f92bdc397495fab33ba7292e414ee
Description
Summary: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.