scholarly journals Thermal oscillations enable reshuffling of genetic material in a primitive cell cycle

2021 ◽  
Author(s):  
Roger Rubio Sanchez ◽  
Derek O'Flaherty ◽  
Anna Wang ◽  
Francesca Coscia ◽  
Lorenzo Di Michele ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Fatty Acid ◽  
Genetic Material ◽  
Darwinian Evolution ◽  
Primitive Cell ◽  
Single Chain ◽  
Cell Cycles ◽  
Self Assembling ◽  
Membrane Components ◽  
Thermal Oscillations

Self-assembling single-chain amphiphiles available in the prebiotic environment likely played a fundamental role in the advent of primitive cell cycles. However, the instability of prebiotic fatty acid-based membranes to temperature and pH seems to suggest that primitive cells could only host prebiotically-relevant processes in a narrow range of non-fluctuating environmental conditions. Here we propose a novel primitive cell cycle driven by environmental fluctuations, which enable the generation of daughter protocells with reshuffled content. A reversible membrane-to-oil phase transition accounts for the dissolution of fatty acid-based vesicles at high temperatures, and the concomitant release of genetic content. At low temperatures, fatty acid bilayers reassemble and encapsulate reshuffled genetic material in a new cohort of protocells. Notably, we find that our disassembly/reassembly cycle drives the emergence of functional RNA-containing primitive cells from parent non-functional compartments. Thus, by exploiting the intrinsic instability of prebiotic fatty acid vesicles, our results point at an environmentally-driven tunable primitive cell cycle, which supports the release and reshuffle of protocellular genetic and membrane components, potentially leading to a new generation of protocells with superior traits. In the absence of protocellular transport machinery, the environmentally-driven disassembly/assembly cycle proposed herein would have supported genetic content reshuffling transmitted to primitive cell progeny, hinting at a potential mechanism important to initiate Darwinian evolution of early lifeforms.

scholarly journals Positive Feedback Between PU.1 and the Cell Cycle Controls Myeloid Differentiation

Science ◽  
2013 ◽  
Vol 341 (6146) ◽  
pp. 670-673 ◽  
Author(s):  
Hao Yuan Kueh ◽  
Ameya Champhekar ◽  
Stephen L. Nutt ◽  
Michael B. Elowitz ◽  
Ellen V. Rothenberg
Keyword(s):  
Cell Cycle ◽  
Cell Fate ◽  
Positive Feedback ◽  
Regulatory Gene ◽  
Control Cell ◽  
Stem Cell Differentiation ◽  
Myeloid Differentiation ◽  
Cycle Duration ◽  
Gene Circuits ◽  
Cell Cycles

Regulatory gene circuits with positive-feedback loops control stem cell differentiation, but several mechanisms can contribute to positive feedback. Here, we dissect feedback mechanisms through which the transcription factor PU.1 controls lymphoid and myeloid differentiation. Quantitative live-cell imaging revealed that developing B cells decrease PU.1 levels by reducing PU.1 transcription, whereas developing macrophages increase PU.1 levels by lengthening their cell cycles, which causes stable PU.1 accumulation. Exogenous PU.1 expression in progenitors increases endogenous PU.1 levels by inducing cell cycle lengthening, implying positive feedback between a regulatory factor and the cell cycle. Mathematical modeling showed that this cell cycle–coupled feedback architecture effectively stabilizes a slow-dividing differentiated state. These results show that cell cycle duration functions as an integral part of a positive autoregulatory circuit to control cell fate.

scholarly journals A Genetic Screen for Suppressors and Enhancers of the Drosophila Cdk1-Cyclin B Identifies Maternal Factors That Regulate Microtubule and Microfilament Stability

Genetics ◽  
2002 ◽  
Vol 162 (3) ◽  
pp. 1179-1195 ◽  
Author(s):  
Jun-Yuan Ji ◽  
Marjan Haghnia ◽  
Cory Trusty ◽  
Lawrence S B Goldstein ◽  
Gerold Schubiger
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Genetic Screen ◽  
Cyclin B ◽  
Gene Products ◽  
Nuclear Movement ◽  
Cell Cycles ◽  
Major Mechanism ◽  
Cytoskeletal Dynamics ◽  
Chromosome Bridges

Abstract Coordination between cell-cycle progression and cytoskeletal dynamics is important for faithful transmission of genetic information. In early Drosophila embryos, increasing maternal cyclin B leads to higher Cdk1-CycB activity, shorter microtubules, and slower nuclear movement during cycles 5-7 and delays in nuclear migration to the cortex at cycle 10. Later during cycle 14 interphase of six cycB embryos, we observed patches of mitotic nuclei, chromosome bridges, abnormal nuclear distribution, and small and large nuclei. These phenotypes indicate disrupted coordination between the cell-cycle machinery and cytoskeletal function. Using these sensitized phenotypes, we performed a dosage-sensitive genetic screen to identify maternal proteins involved in this process. We identified 10 suppressors classified into three groups: (1) gene products regulating Cdk1 activities, cdk1 and cyclin A; (2) gene products interacting with both microtubules and microfilaments, Actin-related protein 87C; and (3) gene products interacting with microfilaments, chickadee, diaphanous, Cdc42, quail, spaghetti-squash, zipper, and scrambled. Interestingly, most of the suppressors that rescue the astral microtubule phenotype also reduce Cdk1-CycB activities and are microfilament-related genes. This suggests that the major mechanism of suppression relies on the interactions among Cdk1-CycB, microtubule, and microfilament networks. Our results indicate that the balance among these different components is vital for normal early cell cycles and for embryonic development. Our observations also indicate that microtubules and cortical microfilaments antagonize each other during the preblastoderm stage.

scholarly journals Genome-Wide Identification and Analysis of Cell Cycle Genes in Birch

Forests ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 120
Author(s):  
Yijie Li ◽  
Song Chen ◽  
Yuhang Liu ◽  
Haijiao Huang
Keyword(s):  
Cell Cycle ◽  
Growth And Development ◽  
Betula Pendula ◽  
Cell Cycle Gene ◽  
Expression Data ◽  
Rna Seq ◽  
Specific Expression ◽  
Cell Cycles ◽  
Cell Cycle Genes ◽  
Genome Wide

Research Highlights: This study identified the cell cycle genes in birch that likely play important roles during the plant’s growth and development. This analysis provides a basis for understanding the regulatory mechanism of various cell cycles in Betula pendula Roth. Background and Objectives: The cell cycle factors not only influence cell cycles progression together, but also regulate accretion, division, and differentiation of cells, and then regulate growth and development of the plant. In this study, we identified the putative cell cycle genes in the B. pendula genome, based on the annotated cell cycle genes in Arabidopsis thaliana (L.) Heynh. It can be used as a basis for further functional research. Materials and Methods: RNA-seq technology was used to determine the transcription abundance of all cell cycle genes in xylem, roots, leaves, and floral tissues. Results: We identified 59 cell cycle gene models in the genome of B. pendula, with 17 highly expression genes among them. These genes were BpCDKA.1, BpCDKB1.1, BpCDKB2.1, BpCKS1.2, BpCYCB1.1, BpCYCB1.2, BpCYCB2.1, BpCYCD3.1, BpCYCD3.5, BpDEL1, BpDpa2, BpE2Fa, BpE2Fb, BpKRP1, BpKRP2, BpRb1, and BpWEE1. Conclusions: By combining phylogenetic analysis and tissue-specific expression data, we identified 17 core cell cycle genes in the Betulapendula genome.

scholarly journals Long-range memory of growth and cycle progression correlates cell cycles in lineage trees

2018 ◽  
Author(s):  
Erika E Kuchen ◽  
Nils Becker ◽  
Nina Claudino ◽  
Thomas Höfer
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Growth ◽  
Mammalian Cell ◽  
Latent Variable ◽  
Cycle Length ◽  
Growth Control ◽  
Minimum Size ◽  
Cell Cycles ◽  
Lineage Trees

Mammalian cell proliferation is controlled by mitogens. However, how proliferation is coordinated with cell growth is poorly understood. Here we show that statistical properties of cell lineage trees – the cell-cycle length correlations within and across generations – reveal how cell growth controls proliferation. Analyzing extended lineage trees with latent-variable models, we find that two antagonistic heritable variables account for the observed cycle-length correlations. Using molecular perturbations of mTOR and MYC we identify these variables as cell size and regulatory license to divide, which are coupled through a minimum-size checkpoint. The checkpoint is relevant only for fast cell cycles, explaining why growth control of mammalian cell proliferation has remained elusive. Thus, correlated fluctuations of the cell cycle encode its regulation.

scholarly journals Multi-CSF-dependent colony formation by cells of a murine hemopoietic cell line: specificity and action of multi-CSF

Blood ◽  
1985 ◽  
Vol 65 (2) ◽  
pp. 357-362 ◽  
Author(s):  
D Metcalf
Keyword(s):  
Cell Cycle ◽  
Cell Line ◽  
High Frequency ◽  
Colony Formation ◽  
Hemopoietic Cell ◽  
Self Renewal ◽  
Cell Cycles ◽  
Cell Numbers ◽  
Gm Csf ◽  
Complete Cell

Abstract Cells of the Multi-CSF (IL-3)-dependent hemopoietic cell line 32D c13 formed colonies of varying size in agar cultures stimulated by Multi- CSF. Colony formation was linear with respect to cultured cell numbers; colony numbers and size increased with increasing concentrations of Multi-CSF, and 32D colonies themselves contained a high frequency of clonogenic cells. Clonogenic 32D cells died in the absence of Multi-CSF (half-life six hours), and most were unable to complete cell cycles in progress at the time of withdrawal of Multi-CSF. The concentration of Multi-CSF directly influenced the length of the cell cycle of dividing 32D cells. Purified GM-CSF, G-CSF, or M-CSF had no capacity to support the survival or proliferation of 32D cells. Colonies formed by 32D cells appear to offer a useful model for analyzing the action of Multi- CSF in controlling self-renewal by clonogenic hemopoietic cells.

scholarly journals Novel localization and possible functions of cyclin E in early sea urchin development

2002 ◽  
Vol 115 (1) ◽  
pp. 113-121 ◽  
Author(s):  
Bradley J. Schnackenberg ◽  
William F. Marzluff
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Sea Urchin ◽  
Kinase Activity ◽  
Cyclin E ◽  
Sperm Head ◽  
Mitotic Spindles ◽  
Paternal Genome ◽  
Cell Cycles ◽  
Cdk2 Activity

In somatic cells, cyclin E-cdk2 activity oscillates during the cell cycle and is required for the regulation of the G1/S transition. Cyclin E and its associated kinase activity remain constant throughout early sea urchin embryogenesis, consistent with reports from studies using several other embryonic systems. Here we have expanded these studies and show that cyclin E rapidly and selectively enters the sperm head after fertilization and remains concentrated in the male pronucleus until pronuclear fusion, at which time it disperses throughout the zygotic nucleus. We also show that cyclin E is not concentrated at the centrosomes but is associated with condensed chromosomes throughout mitosis for at least the first four cell cycles. Isolated mitotic spindles are enriched for cyclin E and cdk2, which are localized to the chromosomes. The chromosomal cyclin E is associated with active kinase during mitosis. We propose that cyclin E may play a role in the remodeling of the sperm head and re-licensing of the paternal genome after fertilization. Furthermore, cyclin E does not need to be degraded or dissociated from the chromosomes during mitosis; instead, it may be required on chromosomes during mitosis to immediately initiate the next round of DNA replication.

scholarly journals EFECTOS DEL SORBATO DE POTASIO A DIFERENTES CONCENTRACIONES y TIEmPO DE ExPOSICIóN SOBRE EL CICLO CELULAR y EL mATERIAL GENÉTICO EN mERISTEmOS RADICULARES DE AllIuM CEPA l. (CEBOLLA)

2019 ◽  
pp. 71-78
Keyword(s):  
Cell Cycle ◽  
Mitotic Index ◽  
Allium Cepa ◽  
Genetic Material ◽  
Potassium Sorbate ◽  
Control Group ◽  
Root Meristems ◽  
Binucleated Cells ◽  
Allium Cepa L ◽  
Ciclo Celular

EFECTOS DEL SORBATO DE POTASIO A DIFERENTES CONCENTRACIONES y TIEmPO DE ExPOSICIóN SOBRE EL CICLO CELULAR y EL mATERIAL GENÉTICO EN mERISTEmOS RADICULARES DE AllIuM CEPA l. (CEBOLLA) EFFECT OF POTASSIUm SORBATE AT DIFFERENT CONCENTRATIONS AND ExPOSURE TImE ON THE CELL CyCLE AND THE GENETIC mATERIAL IN ROOT mERISTEmS OF AllIuM CEPA l “ONION” Joselyne Quispe, José Saldaña, Tony Verde y Shirley Valderrama Universidad Nacional de Trujillo, Trujillo,Perú DOI: https://doi.org/10.33017/RevECIPeru2010.0011/ RESUMEN Con el propósito de determinar el efecto del Sorbato de Potasio sobre el ciclo celular en meristemos radiculares de Allium cepa L. “cebolla” se establecieron tres grupos experimentales que se expusieron a las soluciones de Sorbato de Potasio en concentraciones de 0.5, 1 y 2 g/L; por 6, 7 y 8 horas cada una y un grupo control. Luego se realizó la respectiva coloración en Orceína acética al 2% de acuerdo a la técnica de Tjio y Levan, observándose con el microscopio compuesto un total de 1500 células meristemáticas en cada uno de los tratamientos. Los resultados aplicando tratamiento después de 8 horas de exposición a la concentración de 2 g/L mostraron una disminución del índice mitótico de 11.26 %, mientras que se incrementó el índice profásico en 95.57 %. Se produjeron también alteraciones como rupturas cromosómicas, puentes anafásicos y células binucleadas. Las pruebas y análisis de varianza, mostraron diferencias significativas entre los diferentes tratamientos, confirmado mediante la prueba de comparación múltiple de promedios de Duncan. Se evidencia un probable efecto genotóxico en el material genético por el Sorbato de Potasio y una alteración en el ciclo celular de los meristemos de A. cepa L.; así mismo, se comprueba la función de biosensor de A. cepa L. en el estudio de sustancias que puedan afectar el ciclo celular. Palabras clave: Allium cepa, Sorbato de Potasio, Índice Mitótico, Alteración del material genético, Puentes anafásicos, Rupturas cromosómicas, Células binucleadas. ABSTRACT In order to determine the effect of Potassium Sorbate on the cell cycle in root meristems of Allium cepa L. “onion” set three experimental groups were exposed to solutions of Potassium Sorbate at concentrations of 0.5, 1 and 2g /l, for 6, 7 and 8 hours each and a control group. Later the respective color in 2% Acetic orcein according to the technique of Tjio and Levan, observed with the compound microscope a total of 1500 meristematic cells in each of the treatments. The appropriate treatment results after 8 hours of exposure to the concentration of 2 g / L showed a decrease in mitotic index of 11.26%, while it increased the rate at 95.57% prophasic index. There were also alterations as chromosome breaks, anaphasic bridges and binucleated cells. The tests and analysis of variance showed significant differences between the different treatments, as confirmed by multiple comparison test of Duncan averages. It shows a probable genotoxic effect in the genetic material by Potassium Sorbate and an alteration in the cell cycle of meristems of A. cepa L., likewise, is found biosensor function of A. cepa L. in the study of substances that may affect the cell cycle. Keywords: Allium cepa, Potassium Sorbate, Mitotic index, Abnormal genetic material, Chromosomal breaks, Anafasic bridges, Binucleated cells.

scholarly journals Histone mRNAs Do Not Accumulate during S Phase of either Mitotic or Endoreduplicative Cycles in the Chordate Oikopleura dioica

2004 ◽  
Vol 24 (12) ◽  
pp. 5391-5403 ◽  
Author(s):  
Mariacristina Chioda ◽  
Fabio Spada ◽  
Ragnhild Eskeland ◽  
Eric M. Thompson
Keyword(s):  
Cell Cycle ◽  
S Phase ◽  
Model Organisms ◽  
Promoter Elements ◽  
Oikopleura Dioica ◽  
Stem Loop ◽  
Transcript Levels ◽  
Cell Cycles ◽  
Histone Mrnas ◽  
Complete Cell

ABSTRACT Metazoan histones are generally classified as replication-dependent or replacement variants. Replication-dependent histone genes contain cell cycle-responsive promoter elements, their transcripts terminate in an unpolyadenylated conserved stem-loop, and their mRNAs accumulate sharply during S phase. Replacement variant genes lack cell cycle-responsive promoter elements, their polyadenylated transcripts lack the stem-loop, and they are expressed at low levels throughout the cell cycle. During early development of some organisms with rapid cleavage cycles, replication-dependent mRNAs are not fully S phase restricted until complete cell cycle regulation is achieved. The accumulation of polyadenylated transcripts during this period has been considered incompatible with metazoan development. We show here that histone metabolism in the urochordate Oikopleura dioica does not accord with some key tenets of the replication-dependent/replacement variant paradigm. During the premetamorphic mitotic phase of development, expressed variants shared characteristics of replication-dependent histones, including the 3′ stem-loop, but, in contrast, were extensively polyadenylated. After metamorphosis, when cells in many tissues enter endocycles, there was a global downregulation of histone transcript levels, with most variant transcripts processed at the stem-loop. Contrary to the 30-fold S-phase upregulation of histone transcripts described in common metazoan model organisms, we observed essentially constant histone transcript levels throughout both mitotic and endoreduplicative cell cycles.

Sign in / Sign up

Export Citation Format

Share Document