Programmed Gene Expression During Cell Division Cycles

1982 ◽  
pp. 512-528
Author(s):  
M. Luckner
Keyword(s):  
Gene Expression ◽  
Cell Division

scholarly journals Arabidopsis sepals: A model system for the emergent process of morphogenesis

2021 ◽  
Vol 2 ◽  
Author(s):  
Adrienne H. K. Roeder
Keyword(s):  
Gene Expression ◽  
Arabidopsis Thaliana ◽  
Cell Division ◽  
Slow Growth ◽  
Expression Patterns ◽  
Giant Cells ◽  
Model System ◽  
Gene Expression Patterns ◽  
Emergent Properties ◽  
Correct Size

Abstract During development, Arabidopsis thaliana sepal primordium cells grow, divide and interact with their neighbours, giving rise to a sepal with the correct size, shape and form. Arabidopsis sepals have proven to be a good system for elucidating the emergent processes driving morphogenesis due to their simplicity, their accessibility for imaging and manipulation, and their reproducible development. Sepals undergo a basipetal gradient of growth, with cessation of cell division, slow growth and maturation starting at the tip of the sepal and progressing to the base. In this review, I discuss five recent examples of processes during sepal morphogenesis that yield emergent properties: robust size, tapered tip shape, laminar shape, scattered giant cells and complex gene expression patterns. In each case, experiments examining the dynamics of sepal development led to the hypotheses of local rules. In each example, a computational model was used to demonstrate that these local rules are sufficient to give rise to the emergent properties of morphogenesis.

scholarly journals Extensive Regulation of Metabolism and Growth during the Cell Division Cycle

2014 ◽  
Author(s):  
Nikolai Slavov ◽  
David Botstein ◽  
Amy Caudy
Keyword(s):  
Gene Expression ◽  
Oxygen Consumption ◽  
Cell Division ◽  
Single Cell ◽  
Single Cells ◽  
Emergent Behavior ◽  
Yeast Cells ◽  
Physiological Data ◽  
Synchronized Cultures ◽  
Metabolic Cycle

Yeast cells grown in culture can spontaneously synchronize their respiration, metabolism, gene expression and cell division. Such metabolic oscillations in synchronized cultures reflect single-cell oscillations, but the relationship between the oscillations in single cells and synchronized cultures is poorly understood. To understand this relationship and the coordination between metabolism and cell division, we collected and analyzed DNA-content, gene-expression and physiological data, at hundreds of time-points, from cultures metabolically-synchronized at different growth rates, carbon sources and biomass densities. The data enabled us to extend and generalize our mechanistic model, based on ensemble average over phases (EAP), connecting the population-average gene-expression of asynchronous cultures to the gene-expression dynamics in the single-cells comprising the cultures. The extended model explains the carbon-source specific growth-rate responses of hundreds of genes. Our physiological data demonstrate that the frequency of metabolic cycling in synchronized cultures increases with the biomass density, suggesting that this cycling is an emergent behavior, resulting from the entraining of the single-cell metabolic cycle by a quorum-sensing mechanism, and thus underscoring the difference between metabolic cycling in single cells and in synchronized cultures. Measurements of constant levels of residual glucose across metabolically synchronized cultures indicate that storage carbohydrates are required to fuel not only the G1/S transition of the division cycle but also the metabolic cycle. Despite the large variation in profiled conditions and in the scale of their dynamics, most genes preserve invariant dynamics of coordination with each other and with the rate of oxygen consumption. Similarly, the G1/S transition always occurs at the beginning, middle or end of the high oxygen consumption phases, analogous to observations in human and drosophila cells. These results highlight evolutionary conserved coordination among metabolism, cell growth and division.

scholarly journals Circadian clock components control daily growth activities by modulating cytokinin levels and cell division-associated gene expression in Populus trees

2018 ◽  
Vol 41 (6) ◽  
pp. 1468-1482 ◽  
Author(s):  
Kieron D. Edwards ◽  
Naoki Takata ◽  
Mikael Johansson ◽  
Manuela Jurca ◽  
Ondřej Novák ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Division ◽  
Circadian Clock ◽  
Daily Growth

DNA methylation versus gene expression

Development ◽  
1984 ◽  
Vol 83 (Supplement) ◽  
pp. 31-40
Author(s):  
Adrian P. Bird
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Cell Division ◽  
Methylation Pattern ◽  
Current Evidence ◽  
Evolutionary Perspective ◽  
Cell Type ◽  
Versus Gene ◽  
Daughter Cells ◽  
The Relationship

Vertebrate DNA is methylated at a high proportion of cytosine residues in the sequence CpG, and it has been suggested that the distribution of methylated and non-methylated CpGs in a given cell type influences the pattern of gene expression in those cells. Since a DNA methylation pattern is normally transmitted faithfully to daughter cells via cell division, this idea suggests an origin for stable, clonally inherited patterns of gene expression. This article discusses some of the current evidence for a relationship between DNA methylation and gene expression. Although the evidence is incomplete, it appears already that the relationship is variable: transcription of some genes is repressed by the presence of 5-methylcytosine at certain CpGs, and may be controlled by methylation, while transcription of other genes is indifferent to methylation. In attempting to explain this variability it is helpful to adopt an evolutionary perspective.

scholarly journals Identification of Hub Genes and Potential Molecular Mechanisms in Patients with HBV-Associated Acute Liver Failure

2020 ◽  
Vol 16 ◽  
pp. 117693432094390
Author(s):  
Ying Sun ◽  
Haitao Yu ◽  
Fangfang Li ◽  
Liqiang Lan ◽  
Daxin He ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Division ◽  
Liver Failure ◽  
Acute Liver Failure ◽  
Antigen Processing ◽  
Molecular Mechanisms ◽  
Expression Profiles ◽  
Killer Cell ◽  
Cyclin B1 ◽  
Hub Genes

Hepatitis B virus (HBV) infection is a major cause of acute liver failure (ALF) in China, and mortality rates are high among patients who do not receive a matched liver transplant. This study aimed to determine potential mechanisms involved in HBV-ALF pathogenesis. Gene expression profiles under access numbers GSE38941 and GSE14668 were downloaded from the Gene Expression Omnibus database, including cohorts of HBV-ALF liver tissue and normal samples. Differentially expressed genes (DEGs) with false discovery rates (FDR) <0.05 and |log2(fold change)| >1 as thresholds were screened using the Limma package. Gene modules associated with stable disease were mined using weighed gene co-expression network analysis (WGCNA). A co-expression network was constructed and DEGs were analyzed using gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. A gene-based network was constructed to explore major factors associated with disease progression. We identified 2238 overlapping DEGs as crucial gene cohorts in ALF development. Based on a WGCNA algorithm, 10 modules (modules 1-10) were obtained that ranged from 75 to 1078 genes per module. Cyclin-dependent kinase 1 ( CDK1), cyclin B1 ( CCNB1), and cell-division cycle protein 20 ( CDC20) hub genes were screened using the co-expression network. Furthermore, 17 GO terms and 6 KEGG pathways were identified, such as cell division, immune response process, and antigen processing and presentation. Two overlapping signaling pathways that are crucial factors in HBV-ALF were screened using the Comprehensive Toxicogenomics Database (CTD). Several candidate genes including HLA-E, B2M, HLA-DPA1, and SYK were associated with HBV-ALF progression. Natural killer cell-mediated cytotoxicity and antigen presentation contributed to the progression of HBV-ALF. The HLA-E, B2M, HLA-DPA1, and SYK genes play critical roles in the pathogenesis and development of HBV-ALF.

Platelet-derived growth factor and growth-related genes in rat lung. II. Effect of exposure to 85% O2

1992 ◽  
Vol 262 (2) ◽  
pp. L140-L146 ◽  
Author(s):  
R. N. Han ◽  
S. Buch ◽  
B. A. Freeman ◽  
M. Post ◽  
A. K. Tanswell
Keyword(s):  
Gene Expression ◽  
Cell Division ◽  
Growth Factor ◽  
Receptor Gene ◽  
Platelet Derived Growth Factor ◽  
Chain Gene ◽  
Transcription Analysis ◽  
A Chain ◽  
Type Receptor ◽  
Receptor Gene Expression

The expression of platelet-derived growth factor (PDGF), its receptor, and related genes was studied in the lung tissue of rats exposed to air or 85% O2. PDGF-B chain mRNA was increased by 6 days and PDGF B-type receptor mRNA was increased by 4 and 6 days of exposure to 85% O2. Despite a continued increase of cell division, both PDGF-B chain and B-type receptor mRNAs had returned to control values by 14 days of exposure to 85% O2. PDGF-A chain mRNA was unaffected by exposure to 85% O2. Nuclear runoff transcription analysis confirmed increased transcription of PDGF-B chain mRNA, whereas Western blot analysis of lung homogenates suggested consequent increased translation of PDGF-B chain mRNA to PDGF-BB at 7 days of exposure to 85% O2. Combined immunocytochemistry and autoradiography localized PDGF-BB to the major site of cell division, the pulmonary interstitium. We speculate that the early pulmonary fibroblast hyperplasia observed following exposure to 85% O2 is mediated by increased PDGF-B chain gene expression and may also be mediated by changes in PDGF B-type receptor gene expression.

scholarly journals Compartment-specific transcriptomics of ozone-exposed murine lungs reveals sex and cell type-associated perturbations relevant to mucoinflammatory lung diseases

2020 ◽  
Author(s):  
Ishita Choudhary ◽  
Thao Vo ◽  
Kshitiz Paudel ◽  
Sonika Patial ◽  
Yogesh Saini
Keyword(s):  
Gene Expression ◽  
Dna Repair ◽  
Cell Division ◽  
Mucous Cell ◽  
Ozone Exposure ◽  
Specific Gene ◽  
Cell Type ◽  
Distinct Cell Type ◽  
Airway Injury ◽  
Immunohistochemical Analyses

Ozone is known to cause lung injury and resident cells of the respiratory tract, i.e., epithelial cells and macrophages, respond to inhaled ozone in a variety of ways that affect their survival, morphology, and functioning. However, a complete understanding of the sex-associated and the cell type-specific gene expression changes in response to ozone exposure is still limited. Through transcriptomics, we aimed to analyze gene expression alterations and associated enrichment of biological pathways enrichment in three distinct cell type-enriched compartments of ozone-exposed murine lungs. We sub-chronically exposed adult males and females to 0.8ppm ozone or filtered air. RNA-Seq was performed on airway epithelium-enriched airways, parenchyma, and purified airspace macrophages. Differential gene expression and biological pathway analyses were performed and supported by cellular and immunohistochemical analyses. While a majority of differentially expressed genes (DEGs) in ozone-exposed versus air-exposed groups were common between both sexes, sex-specific DEGs were also identified in all the three tissue compartments. As compared to ozone-exposed males, ozone-exposed females had significant alterations in gene expression in three compartments. Pathways relevant to cell division and DNA repair were enriched in the ozone-exposed airways indicating ozone-induced airway injury and repair which was further supported by immunohistochemical analyses. In addition to cell division and DNA repair pathways, inflammatory pathways were also enriched within the parenchyma supporting contribution by both epithelial and immune cells. Finally, immune response and cytokine-cytokine receptor interactions were enriched in macrophages, indicating ozone-induced macrophage activation. Lastly, our analyses also revealed ozone-induced upregulation of mucoinflammation- and mucous cell metaplasia-associated pathways.

scholarly journals Independence of Circadian Timing from Cell Division in Cyanobacteria

2001 ◽  
Vol 183 (8) ◽  
pp. 2439-2444 ◽  
Author(s):  
Tetsuya Mori ◽  
Carl Hirschie Johnson
Keyword(s):  
Gene Expression ◽  
Cell Division ◽  
Circadian Clock ◽  
Clock Gene ◽  
Circadian Clock Gene ◽  
Circadian Timing ◽  
Wide Range ◽  
Timing System ◽  
Circadian Timing System ◽  
Cell Division Timing

ABSTRACT In the cyanobacterium Synechococcus elongatus, cell division is regulated by a circadian clock. Deletion of the circadian clock gene, kaiC, abolishes rhythms of gene expression and cell division timing. Overexpression of the ftsZ gene halted cell division but not growth, causing cells to grow as filaments without dividing. The nondividing filamentous cells still exhibited robust circadian rhythms of gene expression. This result indicates that the circadian timing system is independent of rhythmic cell division and, together with other results, suggests that the cyanobacterial circadian system is stable and well sustained under a wide range of intracellular conditions.

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