scholarly journals Cell Length Growth in the Fission Yeast Cell Cycle: Is It (Bi)linear or (Bi)exponential?

Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1533
Author(s):  
Benedek Pesti ◽  
Zsófia Nagy ◽  
László Papp ◽  
Matthias Sipiczki ◽  
Ákos Sveiczer
Keyword(s):  
Fission Yeast ◽  
Mitotic Cycle ◽  
Model Fitting ◽  
Model Organism ◽  
Eukaryotic Cell ◽  
Growth Patterns ◽  
Wild Type ◽  
Length Growth ◽  
Bilinear Models ◽  
Bilinear Functions

Fission yeast is commonly used as a model organism in eukaryotic cell growth studies. To describe the cells’ length growth patterns during the mitotic cycle, different models have been proposed previously as linear, exponential, bilinear and biexponential ones. The task of discriminating among these patterns is still challenging. Here, we have analyzed 298 individual cells altogether, namely from three different steady-state cultures (wild-type, wee1-50 mutant and pom1Δ mutant). We have concluded that in 190 cases (63.8%) the bilinear model was more adequate than either the linear or the exponential ones. These 190 cells were further examined by separately analyzing the linear segments of the best fitted bilinear models. Linear and exponential functions have been fitted to these growth segments to determine whether the previously fitted bilinear functions were really correct. The majority of these growth segments were found to be linear; nonetheless, a significant number of exponential ones were also detected. However, exponential ones occurred mainly in cases of rather short segments (<40 min), where there were not enough data for an accurate model fitting. By contrast, in long enough growth segments (≥40 min), linear patterns highly dominated over exponential ones, verifying that overall growth is probably bilinear.

Pseudo-exponential growth in length of the fission yeast, Schizosaccharomyces pombe

1988 ◽  
Vol 34 (12) ◽  
pp. 1338-1343 ◽  
Author(s):  
Hisao Miyata ◽  
Machiko Miyata ◽  
Byron F. Johnson
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Exponential Growth ◽  
Linear Growth ◽  
Normal Growth ◽  
Growth Patterns ◽  
Birth Length ◽  
Yeast Cells ◽  
Wild Type ◽  
Constant Length

The growth patterns of individual cells of the fission yeast (Schizosaccharomyces pombe wild-type cells, strain 972 h−; cells exposed to hydroxyurea; and cdc mutants, 11-123, 2-33) were investigated by time-lapse photomicrography. Wild-type cells showed one, two, or three linear-growth segments followed by a constant-length stage. Cells with two segments were most frequent. Hydroxyurea cells that divided as oversized cells (about three times the birth length) had three linear-growth segments in a cycle. Mutant cdc11-123 cells did not divide but had a constant-length stage separating the cycles; both the first and second cycles consisted of two linear-growth segments, and cells were oversized at the second constant-length stage (about 3.5 times the birth length). Elongating cdc2-33 cells that did not divide and were oversized (about five times the birth length) while under observation, showed four linear-growth segments. Cells of all strains showed 30 to 40% increase in growth rate at the rate-change point and maintained approximate exponential (pseudo-exponential) growth. We conclude that the normal growth pattern of individual fission-yeast cells is the pseudo-exponential pattern.

scholarly journals imp2, a New Component of the Actin Ring in the Fission Yeast Schizosaccharomyces pombe

1998 ◽  
Vol 143 (2) ◽  
pp. 415-427 ◽  
Author(s):  
Janos Demeter ◽  
Shelley Sazer
Keyword(s):  
Cell Division ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Model Organism ◽  
Eukaryotic Cell ◽  
Actin Ring ◽  
Daughter Cells ◽  
Isolation And Characterization ◽  
Ring Structures

Cytokinesis is the part of the cell cycle in which the cell is cleaved to form two daughter cells. The unicellular yeast, Schizosaccharomyces pombe is an excellent model organism in which to study cell division, since it shows the general features of eukaryotic cell division and is amenable to genetic analysis. In this manuscript we describe the isolation and characterization of a new protein, imp2, which is required for normal septation in fission yeast. imp2, which colocalizes with the medial ring during septation, is structurally similar to a group of proteins including the S. pombe cdc15 and the mouse PSTPIP that are localized to, and thought to be involved in actin ring organization. Cells in which the imp2 gene is deleted or overexpressed have septation and cell separation defects. An analysis of the actin cytoskeleton shows the lack of a medial ring in septating cells that overexpress imp2, and the appearance of abnormal medial ring structures in septated cells that lack imp2. These observations suggest that imp2 destabilizes the medial ring during septation. imp2 also shows genetic interactions with several, previously characterized septation genes, strengthening the conclusion that it plays a role in normal fission yeast septation.

Different mechanisms of cell polarisation in vegetative and shmooing growth in fission yeast

2002 ◽  
Vol 115 (8) ◽  
pp. 1651-1662 ◽  
Author(s):  
Teresa Niccoli ◽  
Paul Nurse
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Vegetative Growth ◽  
Growth Patterns ◽  
Growth Mode ◽  
Wild Type ◽  
Vegetative Cells ◽  
Form Part

Schizosaccharomyces pombe cells have two polarised growth modes:an intrinsic vegetative growth mode, determined by an internal positioning mechanism and an extrinsic shmooing growth mode, activated by external pheromone. We have analysed the role of the cell end marker Tea1p, the CLIP170 like protein Tip1p, the kinesin like protein Tea2p and the Dyrk-like kinase Pom1p, during the switch between the two growth patterns, with the intention of studying the switch away from the vegetative growth mode. In vegetative growth these morphological factors are concentrated at cell ends, whereas during shmooing growth they are delocalised from the cell ends. In the absence of Tea1p, Tip1p and Tea2p, vegetative cells display microtubule and cell polarisation defects, but shmooing cells are indistinguishable from wild-type and shmoo more readily. These results suggest that Tea1p, Tip1p and Tea2p are not required for polarised growth during shmooing, but form part of the intrinsic vegetative growth mode that needs to be dismantled before cells can generate an extrinsic growth patterns. In contrast, Pom1p appears to have a role in the initial stages of the switch to the shmooing growth mode.

scholarly journals Cadmium-Induced Cell Homeostasis Impairment is Suppressed by the Tor1 Deficiency in Fission Yeast

2020 ◽  
Vol 21 (21) ◽  
pp. 7847
Author(s):  
Miroslava Požgajová ◽  
Alica Navrátilová ◽  
Eva Šebová ◽  
Marek Kovár ◽  
Miroslava Kačániová
Keyword(s):  
Fission Yeast ◽  
Inductively Coupled Plasma ◽  
Defense Mechanisms ◽  
Model Organism ◽  
Optical Emission ◽  
The Body ◽  
Wild Type ◽  
Cd Uptake ◽  
Underlying Mechanisms

Cadmium has no known physiological function in the body; however, its adverse effects are associated with cancer and many types of organ system damage. Although much has been shown about Cd toxicity, the underlying mechanisms of its responses to the organism remain unclear. In this study, the role of Tor1, a catalytic subunit of the target of rapamycin complex 2 (TORC2), in Cd-mediated effects on cell proliferation, the antioxidant system, morphology, and ionome balance was investigated in the eukaryotic model organism Schizosaccharomyces pombe. Surprisingly, spectrophotometric and biochemical analyses revealed that the growth rate conditions and antioxidant defense mechanisms are considerably better in cells lacking the Tor1 signaling. The malondialdehyde (MDA) content of Tor1-deficient cells upon Cd treatment represents approximately half of the wild-type content. The microscopic determination of the cell morphological parameters indicates the role for Tor1 in cell shape maintenance. The ion content, determined by inductively coupled plasma optical emission spectroscopy (ICP-OES), showed that the Cd uptake potency was markedly lower in Tor1-depleted compared to wild-type cells. Conclusively, we show that the cadmium-mediated cell impairments in the fission yeast significantly depend on the Tor1 signaling. Additionally, the data presented here suggest the yet-undefined role of Tor1 in the transport of ions.

Modelling the CDK-dependent transcription cycle in fission yeast

2013 ◽  
Vol 41 (6) ◽  
pp. 1660-1665 ◽  
Author(s):  
Miriam Sansó ◽  
Robert P. Fisher
Keyword(s):  
Fission Yeast ◽  
Rna Polymerase Ii ◽  
Genetic Model ◽  
Current Knowledge ◽  
Cell Cycle Control ◽  
Model Organism ◽  
Eukaryotic Cell ◽  
Chromatin Modifications ◽  
Cyclin Dependent Kinases ◽  
Transcription Cycle

CDKs (cyclin-dependent kinases) ensure directionality and fidelity of the eukaryotic cell division cycle. In a similar fashion, the transcription cycle is governed by a conserved subfamily of CDKs that phosphorylate Pol II (RNA polymerase II) and other substrates. A genetic model organism, the fission yeast Schizosaccharomyces pombe, has yielded robust models of cell-cycle control, applicable to higher eukaryotes. From a similar approach combining classical and chemical genetics, fundamental principles of transcriptional regulation by CDKs are now emerging. In the present paper, we review the current knowledge of each transcriptional CDK with respect to its substrate specificity, function in transcription and effects on chromatin modifications, highlighting the important roles of CDKs in ensuring quantity and quality control over gene expression in eukaryotes.

Cell length growth patterns in fission yeast reveal a novel size control mechanism operating in late G2 phase

2016 ◽  
Vol 108 (9) ◽  
pp. 259-277 ◽  
Author(s):  
Anna Horváth ◽  
Anna Rácz-Mónus ◽  
Peter Buchwald ◽  
Ákos Sveiczer
Keyword(s):  
Fission Yeast ◽  
Control Mechanism ◽  
Size Control ◽  
Growth Patterns ◽  
Cell Length ◽  
Length Growth ◽  
G2 Phase

scholarly journals The Multiple Functions of Rho GTPases in Fission Yeasts

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1422
Author(s):  
Jero Vicente-Soler ◽  
Teresa Soto ◽  
Alejandro Franco ◽  
José Cansado ◽  
Marisa Madrid
Keyword(s):  
Fission Yeast ◽  
Rho Gtpases ◽  
Current Knowledge ◽  
Model Organism ◽  
Nucleotide Exchange ◽  
Guanine Nucleotide Exchange ◽  
Nucleotide Exchange Factors ◽  
Physiological Processes ◽  
Evolutionary Changes ◽  
Rho Family

The Rho family of GTPases represents highly conserved molecular switches involved in a plethora of physiological processes. Fission yeast Schizosaccharomyces pombe has become a fundamental model organism to study the functions of Rho GTPases over the past few decades. In recent years, another fission yeast species, Schizosaccharomyces japonicus, has come into focus offering insight into evolutionary changes within the genus. Both fission yeasts contain only six Rho-type GTPases that are spatiotemporally controlled by multiple guanine–nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs), and whose intricate regulation in response to external cues is starting to be uncovered. In the present review, we will outline and discuss the current knowledge and recent advances on how the fission yeasts Rho family GTPases regulate essential physiological processes such as morphogenesis and polarity, cellular integrity, cytokinesis and cellular differentiation.

scholarly journals Lactose-Inducible System for Metabolic Engineering of Clostridium ljungdahlii

2014 ◽  
Vol 80 (8) ◽  
pp. 2410-2416 ◽  
Author(s):  
Areen Banerjee ◽  
Ching Leang ◽  
Toshiyuki Ueki ◽  
Kelly P. Nevin ◽  
Derek R. Lovley
Keyword(s):  
Ethanol Production ◽  
Genetic Manipulation ◽  
Electron Flow ◽  
Model Organism ◽  
Inducible Expression ◽  
Carbon Flow ◽  
Wild Type ◽  
Content Type ◽  
Microbial Electrosynthesis ◽  
Clostridium Ljungdahlii

ABSTRACTThe development of tools for genetic manipulation ofClostridium ljungdahliihas increased its attractiveness as a chassis for autotrophic production of organic commodities and biofuels from syngas and microbial electrosynthesis and established it as a model organism for the study of the basic physiology of acetogenesis. In an attempt to expand the genetic toolbox forC. ljungdahlii, the possibility of adapting a lactose-inducible system for gene expression, previously reported forClostridium perfringens, was investigated. The plasmid pAH2, originally developed forC. perfringenswith agusAreporter gene, functioned as an effective lactose-inducible system inC. ljungdahlii. Lactose induction ofC. ljungdahliicontaining pB1, in which the gene for the aldehyde/alcohol dehydrogenase AdhE1 was downstream of the lactose-inducible promoter, increased expression ofadhE130-fold over the wild-type level, increasing ethanol production 1.5-fold, with a corresponding decrease in acetate production. Lactose-inducible expression ofadhE1in a strain in whichadhE1and theadhE1homologadhE2had been deleted from the chromosome restored ethanol production to levels comparable to those in the wild-type strain. Inducing expression ofadhE2similarly failed to restore ethanol production, suggesting thatadhE1is the homolog responsible for ethanol production. Lactose-inducible expression of the four heterologous genes necessary to convert acetyl coenzyme A (acetyl-CoA) to acetone diverted ca. 60% of carbon flow to acetone production during growth on fructose, and 25% of carbon flow went to acetone when carbon monoxide was the electron donor. These studies demonstrate that the lactose-inducible system described here will be useful for redirecting carbon and electron flow for the biosynthesis of products more valuable than acetate. Furthermore, this tool should aid in optimizing microbial electrosynthesis and for basic studies on the physiology of acetogenesis.

scholarly journals Amino acids whose intracellular levels change most during aging alter chronological lifespan of fission yeast

2020 ◽  
Author(s):  
Charalampos Rallis ◽  
Michael Mülleder ◽  
Graeme Smith ◽  
Yan Zi Au ◽  
Markus Ralser ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Fission Yeast ◽  
Yeast Cells ◽  
Total Amino Acid ◽  
Wild Type ◽  
Chronological Lifespan ◽  
Biomarkers Of Aging ◽  
Concentration Changes ◽  
Amino Acid Levels

AbstractAmino acid deprivation or supplementation can affect cellular and organismal lifespan, but we know little about the role of concentration changes in free, intracellular amino acids during aging. Here, we determine free amino-acid levels during chronological aging of non-dividing fission yeast cells. We compare wild-type with long-lived mutant cells that lack the Pka1 protein of the protein kinase A signalling pathway. In wild-type cells, total amino-acid levels decrease during aging, but much less so in pka1 mutants. Two amino acids strongly change as a function of age: glutamine decreases, especially in wild-type cells, while aspartate increases, especially in pka1 mutants. Supplementation of glutamine is sufficient to extend the chronological lifespan of wild-type but not of pka1Δ cells. Supplementation of aspartate, on the other hand, shortens the lifespan of pka1Δ but not of wild-type cells. Our results raise the possibility that certain amino acids are biomarkers of aging, and their concentrations during aging can promote or limit cellular lifespan.

scholarly journals A toolbox of Stable Integration Vectors (SIV) in the fission yeast Schizosaccharomyces pombe

2019 ◽  
Author(s):  
Aleksandar Vještica ◽  
Magdalena Marek ◽  
Pedro N’kosi ◽  
Laura Merlini ◽  
Gaowen Liu ◽  
...  
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Model Organism ◽  
Experimental System ◽  
Single Copy ◽  
Cell Physiology ◽  
Large Set ◽  
Stable Integration ◽  
Wide Range ◽  
Fluorescent Tags

AbstractSchizosaccharomyces pombe is a widely used model organism that resembles higher eukaryotes in many aspects of cell physiology. Its popularity as an experimental system partially stems from the ease of genetic manipulations, where the innate homology-targeted repair is exploited to precisely edit the genome. While vectors to incorporate exogenous sequences into the chromosomes are available, most are poorly characterized. Here we show that commonly used fission yeast vectors, which upon integration produce repetitive genomic regions, yield unstable genomic loci. We overcome this problem by designing a new series of Stable Integration Vectors (SIV) that target four different prototrophy genes. SIV produce non-repetitive, stable genomic loci and integrate predominantly as single copy. Additionally, we develop a set of complementary auxotrophic alleles that preclude false-positive integration events. We expand the vector series to include antibiotic resistance markers, promoters, fluorescent tags and terminators, and build a highly modular toolbox to introduce heterologous sequences. Finally, as proof of concept, we generate a large set of ready-to-use, fluorescent probes to mark organelles and cellular processes with a wide range of applications in fission yeast research.

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