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Current Biology : CB Nov 2012During mitosis and meiosis, the spindle assembly checkpoint acts to maintain genome stability by delaying cell division until accurate chromosome segregation can be... (Review)
Review
During mitosis and meiosis, the spindle assembly checkpoint acts to maintain genome stability by delaying cell division until accurate chromosome segregation can be guaranteed. Accuracy requires that chromosomes become correctly attached to the microtubule spindle apparatus via their kinetochores. When not correctly attached to the spindle, kinetochores activate the spindle assembly checkpoint network, which in turn blocks cell cycle progression. Once all kinetochores become stably attached to the spindle, the checkpoint is inactivated, which alleviates the cell cycle block and thus allows chromosome segregation and cell division to proceed. Here we review recent progress in our understanding of how the checkpoint signal is generated, how it blocks cell cycle progression and how it is extinguished.
Topics: Animals; Cell Division; Gene Expression Regulation; Kinetochores; M Phase Cell Cycle Checkpoints
PubMed: 23174302
DOI: 10.1016/j.cub.2012.10.006 -
WormBook : the Online Review of C.... May 2017Sexual reproduction requires the production of haploid gametes (sperm and egg) with only one copy of each chromosome; fertilization then restores the diploid chromosome... (Review)
Review
Sexual reproduction requires the production of haploid gametes (sperm and egg) with only one copy of each chromosome; fertilization then restores the diploid chromosome content in the next generation. This reduction in genetic content is accomplished during a specialized cell division called meiosis, in which two rounds of chromosome segregation follow a single round of DNA replication. In preparation for the first meiotic division, homologous chromosomes pair and synapse, creating a context that promotes formation of crossover recombination events. These crossovers, in conjunction with sister chromatid cohesion, serve to connect the two homologs and facilitate their segregation to opposite poles during the first meiotic division. During the second meiotic division, which is similar to mitosis, sister chromatids separate; the resultant products are haploid cells that become gametes. In Caenorhabditis elegans (and most other eukaryotes) homologous pairing and recombination are required for proper chromosome inheritance during meiosis; accordingly, the events of meiosis are tightly coordinated to ensure the proper execution of these events. In this chapter, we review the seminal events of meiosis: pairing of homologous chromosomes, the changes in chromosome structure that chromosomes undergo during meiosis, the events of meiotic recombination, the differentiation of homologous chromosome pairs into structures optimized for proper chromosome segregation at Meiosis I, and the ultimate segregation of chromosomes during the meiotic divisions. We also review the regulatory processes that ensure the coordinated execution of these meiotic events during prophase I.
Topics: Animals; Caenorhabditis elegans; Cell Division; Chromosome Segregation; Chromosomes; Meiosis; Meiotic Prophase I; Recombination, Genetic
PubMed: 26694509
DOI: 10.1895/wormbook.1.178.1 -
Developmental Cell Mar 2004The Keystone Symposium on the Cell Cycle and Development brought together biologists with an interest in how cell cycle control is integrated into the ontogenetic... (Review)
Review
The Keystone Symposium on the Cell Cycle and Development brought together biologists with an interest in how cell cycle control is integrated into the ontogenetic program of multicellular organisms, and showcased research using a wide variety of systems from both animals and plants. A clear indication from the meeting is that this research is changing the conventional wisdom on both cell cycle control and development.
Topics: Animals; Cell Communication; Cell Cycle; Cell Differentiation; Cell Division; DNA Replication; Models, Biological; Morphogenesis; Plants
PubMed: 15030756
DOI: 10.1016/s1534-5807(04)00067-x -
Journal of Bacteriology Nov 2019Reproduction in the bacterial kingdom predominantly occurs through binary fission-a process in which one parental cell is divided into two similarly sized daughter... (Review)
Review
Reproduction in the bacterial kingdom predominantly occurs through binary fission-a process in which one parental cell is divided into two similarly sized daughter cells. How cell division, in conjunction with cell elongation and chromosome segregation, is orchestrated by a multitude of proteins has been an active area of research spanning the past few decades. Together, the monumental endeavors of multiple laboratories have identified several cell division and cell shape regulators as well as their underlying regulatory mechanisms in rod-shaped and , which serve as model organisms for Gram-negative and Gram-positive bacteria, respectively. Yet our understanding of bacterial cell division and morphology regulation is far from complete, especially in noncanonical and non-rod-shaped organisms. In this review, we focus on two proteins that are highly conserved in Gram-positive organisms, DivIVA and its homolog GpsB, and attempt to summarize the recent advances in this area of research and discuss their various roles in cell division, cell growth, and chromosome segregation in addition to their interactome and posttranslational regulation.
Topics: Bacillus subtilis; Bacterial Proteins; Cell Division; Cell Proliferation; Chromosome Segregation; Protein Processing, Post-Translational
PubMed: 31405912
DOI: 10.1128/JB.00245-19 -
Seminars in Cell & Developmental Biology Jul 2022Cytokinesis is a mechanism that separates dividing cells via constriction of a supramolecular structure, the contractile ring. In animal cells, three modes of... (Review)
Review
Cytokinesis is a mechanism that separates dividing cells via constriction of a supramolecular structure, the contractile ring. In animal cells, three modes of symmetry-breaking of cytokinesis result in unilateral cytokinesis, asymmetric cell division, and oriented cell division. Each mode of cytokinesis plays a significant role in tissue patterning and morphogenesis by the mechanisms that control the orientation and position of the contractile ring relative to the body axis. Despite its significance, the mechanisms involved in the symmetry-breaking of cytokinesis remain unclear in many cell types. Classical embryologists have identified that the geometric relationship between the mitotic spindle and cell cortex induces cytokinesis asymmetry; however, emerging evidence suggests that a concerted flow of compressional cell-cortex materials (cortical flow) is a spindle-independent driving force in spatial cytokinesis control. This review provides an overview of both classical and emerging mechanisms of cytokinesis asymmetry and their roles in animal development.
Topics: Actin Cytoskeleton; Animals; Cell Division; Cytokinesis; Spindle Apparatus
PubMed: 34955355
DOI: 10.1016/j.semcdb.2021.12.008 -
Current Biology : CB May 2021As the interface between the cell and its environment, the cell cortex must be able to respond to a variety of external stimuli. This is made possible in part by...
As the interface between the cell and its environment, the cell cortex must be able to respond to a variety of external stimuli. This is made possible in part by cortical excitability, a behavior driven by coupled positive and negative feedback loops that generate propagating waves of actin assembly in the cell cortex. Cortical excitability is best known for promoting cell protrusion and allowing the interpretation of and response to chemoattractant gradients in migrating cells. It has recently become apparent, however, that cortical excitability is involved in the response of the cortex to internal signals from the cell-cycle regulatory machinery and the spindle during cell division. Two overlapping functions have been ascribed to cortical excitability in cell division: control of cell division plane placement, and amplification of the activity of the small GTPase Rho at the equatorial cortex during cytokinesis. Here, we propose that cortical excitability explains several important yet poorly understood features of signaling during cell division. We also consider the potential advantages that arise from the use of cortical excitability as a signaling mechanism to regulate cortical dynamics in cell division.
Topics: Actins; Cell Division; Cytokinesis; Cytoplasm; Signal Transduction
PubMed: 34033789
DOI: 10.1016/j.cub.2021.02.053 -
Genes & Development Mar 2009Cytokinesis is the terminal step of the cell cycle during which a mother cell divides into daughter cells. Often, the machinery of cytokinesis is positioned in such a... (Review)
Review
Cytokinesis is the terminal step of the cell cycle during which a mother cell divides into daughter cells. Often, the machinery of cytokinesis is positioned in such a way that daughter cells are born roughly equal in size. However, in many specialized cell types or under certain environmental conditions, the cell division machinery is placed at nonmedial positions to produce daughter cells of different sizes and in many cases of different fates. Here we review the different mechanisms that position the division machinery in prokaryotic and eukaryotic cell types. We also describe cytokinesis-positioning mechanisms that are not adequately explained by studies in model organisms and model cell types.
Topics: Animals; Biological Evolution; Cell Division; Cell Shape; Cytokinesis; Humans; Microtubules; Spindle Apparatus
PubMed: 19299557
DOI: 10.1101/gad.1772009 -
Journal of Cell Science Apr 2020Bacterial cell division is initiated by the midcell assembly of polymers of the tubulin-like GTPase FtsZ. The FtsZ ring (Z-ring) is a discontinuous structure made of... (Review)
Review
Bacterial cell division is initiated by the midcell assembly of polymers of the tubulin-like GTPase FtsZ. The FtsZ ring (Z-ring) is a discontinuous structure made of dynamic patches of FtsZ that undergo treadmilling motion. Roughly a dozen additional essential proteins are recruited to the division site by the dynamic Z-ring scaffold and subsequently activate cell wall synthesis to drive cell envelope constriction during division. In this Cell Science at a Glance article and the accompanying poster, we summarize our understanding of the assembly and activation of the bacterial cell division machinery. We introduce polymerization properties of FtsZ and discuss our current knowledge of divisome assembly and activation. We further highlight the intimate relationship between the structure and dynamics of FtsZ and the movement and activity of cell wall synthases at the division site, before concluding with a perspective on the most important open questions on bacterial cell division.
Topics: Bacterial Proteins; Cell Division; Cell Wall; Cytokinesis; Cytoskeletal Proteins
PubMed: 32269092
DOI: 10.1242/jcs.237057 -
The Journal of Biological Chemistry Jul 2019Cell division is a highly regulated and carefully orchestrated process. Understanding the mechanisms that promote proper cell division is an important step toward... (Review)
Review
Cell division is a highly regulated and carefully orchestrated process. Understanding the mechanisms that promote proper cell division is an important step toward unraveling important questions in cell biology and human health. Early studies seeking to dissect the mechanisms of cell division used classical genetics approaches to identify genes involved in mitosis and deployed biochemical approaches to isolate and identify proteins critical for cell division. These studies underscored that post-translational modifications and cyclin-kinase complexes play roles at the heart of the cell division program. Modern approaches for examining the mechanisms of cell division, including the use of high-throughput methods to study the effects of RNAi, cDNA, and chemical libraries, have evolved to encompass a larger biological and chemical space. Here, we outline some of the classical studies that established a foundation for the field and provide an overview of recent approaches that have advanced the study of cell division.
Topics: Animals; Cell Division; DNA, Complementary; Humans; Protein Processing, Post-Translational; Proteomics; RNA Interference
PubMed: 31175154
DOI: 10.1074/jbc.AW119.008149 -
Nature Chemical Biology Jun 2021Components of the cell division machinery typically function at varying cell cycle stages and intracellular locations. To dissect cellular mechanisms during the rapid... (Review)
Review
Components of the cell division machinery typically function at varying cell cycle stages and intracellular locations. To dissect cellular mechanisms during the rapid division process, small-molecule probes act as complementary approaches to genetic manipulations, with advantages of temporal and in some cases spatial control and applicability to multiple model systems. This Review focuses on recent advances in chemical probes and applications to address select questions in cell division. We discuss uses of both enzyme inhibitors and chemical inducers of dimerization, as well as emerging techniques to promote future investigations. Overall, these concepts may open new research directions for applying chemical probes to advance cell biology.
Topics: Animals; Cell Biology; Cell Cycle; Cell Division; Genetic Techniques; Humans
PubMed: 34035515
DOI: 10.1038/s41589-021-00798-3