scholarly journals A Spatiotemporal Molecular Switch Governs Plant Asymmetric Cell Division

2020 ◽  
Author(s):  
Xiaoyu Guo ◽  
Chan Ho Park ◽  
Zhi-Yong Wang ◽  
Bryce E. Nickels ◽  
Juan Dong

SummaryAsymmetric cell division (ACD) often requires protein polarization in the mother cell to produce daughter cells with distinct identities (“cell-fate asymmetry”). Here, we define a previously undocumented mechanism for establishing cell-fate asymmetry in Arabidopsis stomatal stem cells. In particular, we show that polarization of BSL protein phosphatases promotes stomatal ACD by establishing a “kinase-based signaling asymmetry” in the two daughter cells. BSL polarization in the stomatal ACD mother cell is triggered upon commitment to cell division. Polarized BSL is inherited by the differentiating daughter cell where it suppresses cell division and promotes cell-fate determination. Plants lacking BSL exhibit stomatal over-proliferation, demonstrating BSL plays an essential role in stomatal development. Our findings establish that BSL polarization provides a spatiotemporal molecular switch that enables cell-fate asymmetry in stomatal ACD daughter cells. We propose BSL polarization is triggered by an ACD “checkpoint” in the mother cell that monitors establishment of division-plane asymmetry.

2010 ◽  
Vol 107 (5) ◽  
pp. 2195-2200 ◽  
Author(s):  
Sharon R. Pine ◽  
Bríd M. Ryan ◽  
Lyuba Varticovski ◽  
Ana I. Robles ◽  
Curtis C. Harris

Normal tissue homeostasis is maintained through asymmetric cell divisions that produce daughter cells with differing self-renewal and differentiation potentials. Certain tumor cell subfractions can self-renew and repopulate the heterogeneous tumor bulk, suggestive of asymmetric cell division, but an equally plausible explanation is that daughter cells of a symmetric division subsequently adopt differing cell fates. Cosegregation of template DNA during mitosis is one mechanism by which cellular components are segregated asymmetrically during cell division in fibroblast, muscle, mammary, intestinal, and neural cells. Asymmetric cell division of template DNA in tumor cells has remained elusive, however. Through pulse-chase experiments with halogenated thymidine analogs, we determined that a small population of cells within human lung cancer cell lines and primary tumor cell cultures asymmetrically divided their template DNA, which could be visualized in single cells and in real time. Template DNA cosegregation was enhanced by cell–cell contact. Its frequency was density-dependent and modulated by environmental changes, including serum deprivation and hypoxia. In addition, we found that isolated CD133+ lung cancer cells were capable of tumor cell repopulation. Strikingly, during cell division, CD133 cosegregated with the template DNA, whereas the differentiation markers prosurfactant protein-C and pan-cytokeratins were passed to the opposing daughter cell, demonstrating that segregation of template DNA correlates with lung cancer cell fate. Our results demonstrate that human lung tumor cell fate decisions may be regulated during the cell division process. The characterization and modulation of asymmetric cell division in lung cancer can provide insight into tumor initiation, growth, and maintenance.


2015 ◽  
Vol 40 (5) ◽  
pp. 921-927 ◽  
Author(s):  
Mani Arora ◽  
Arga Chandrashekar Anil ◽  
Karl Burgess ◽  
Jane Delany ◽  
Ehsan Mesbahi

2020 ◽  
Vol 64 (2) ◽  
pp. 223-232 ◽  
Author(s):  
Ben L. Carty ◽  
Elaine M. Dunleavy

Abstract Asymmetric cell division (ACD) produces daughter cells with separate distinct cell fates and is critical for the development and regulation of multicellular organisms. Epigenetic mechanisms are key players in cell fate determination. Centromeres, epigenetically specified loci defined by the presence of the histone H3-variant, centromere protein A (CENP-A), are essential for chromosome segregation at cell division. ACDs in stem cells and in oocyte meiosis have been proposed to be reliant on centromere integrity for the regulation of the non-random segregation of chromosomes. It has recently been shown that CENP-A is asymmetrically distributed between the centromeres of sister chromatids in male and female Drosophila germline stem cells (GSCs), with more CENP-A on sister chromatids to be segregated to the GSC. This imbalance in centromere strength correlates with the temporal and asymmetric assembly of the mitotic spindle and potentially orientates the cell to allow for biased sister chromatid retention in stem cells. In this essay, we discuss the recent evidence for asymmetric sister centromeres in stem cells. Thereafter, we discuss mechanistic avenues to establish this sister centromere asymmetry and how it ultimately might influence cell fate.


Nature Plants ◽  
2021 ◽  
Author(s):  
Xiaoyu Guo ◽  
Chan Ho Park ◽  
Zhi-Yong Wang ◽  
Bryce E. Nickels ◽  
Juan Dong

2001 ◽  
Vol 114 (23) ◽  
pp. 4319-4328
Author(s):  
Sherryl R. Bisgrove ◽  
Darryl L. Kropf

The first cell division in zygotes of the fucoid brown alga Pelvetia compressa is asymmetric and we are interested in the mechanism controlling the alignment of this division. Since the division plane bisects the mitotic apparatus, we investigated the timing and mechanism of spindle alignments. Centrosomes, which give rise to spindle poles, aligned with the growth axis in two phases – a premetaphase rotation of the nucleus and centrosomes followed by a postmetaphase alignment that coincided with the separation of the mitotic spindle poles during anaphase and telophase. The roles of the cytoskeleton and cell cortex in the two phases of alignment were analyzed by treatment with pharmacological agents. Treatments that disrupted cytoskeleton or perturbed cortical adhesions inhibited pre-metaphase alignment and we propose that this rotational alignment is effected by microtubules anchored at cortical adhesion sites. Postmetaphase alignment was not affected by any of the treatments tested, and may be dependent on asymmetric cell morphology.


Blood ◽  
2021 ◽  
Author(s):  
Dirk Loeffler ◽  
Florin Schneiter ◽  
Weijia Wang ◽  
Arne Wehling ◽  
Tobias Kull ◽  
...  

Understanding human hematopoietic stem cell fate control is important for their improved therapeutic manipulation. Asymmetric cell division, the asymmetric inheritance of factors during division instructing future daughter cell fates, was recently described in mouse blood stem cells. In human blood stem cells, the possible existence of asymmetric cell division remained unclear due to technical challenges in its direct observation. Here, we use long-term quantitative single-cell imaging to show that lysosomes and active mitochondria are asymmetrically inherited in human blood stem cells and that their inheritance is a coordinated, non-random process. Furthermore, multiple additional organelles, including autophagosomes, mitophagosomes, autolysosomes and recycling endosomes show preferential asymmetric co-segregation with lysosomes. Importantly, asymmetric lysosomal inheritance predicts future asymmetric daughter cell cycle length, differentiation and stem cell marker expression, while asymmetric inheritance of active mitochondria correlates with daughter metabolic activity. Hence, human hematopoietic stem cell fates are regulated by asymmetric cell division, with both mechanistic evolutionary conservation and differences to the mouse system.


2021 ◽  
Vol 119 ◽  
pp. 432-443
Author(s):  
Yanqun Li ◽  
Jianhui Yue ◽  
Yuan Liu ◽  
Jun Wu ◽  
Min Guan ◽  
...  

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