Sexual co-flocculation and asexual self-flocculation of heterothallic fission-yeast cells(Schizosaccharomyces pombe)

1987 ◽  
Vol 33 (8) ◽  
pp. 684-688 ◽  
Author(s):  
Byron F. Johnson ◽  
Teena Walker ◽  
Machiko Miyata ◽  
Hisao Miyata ◽  
G. B. Calleja

Culturing conditions have been found that engender flocculation of strains 975h+ and 972h− of the fission yeast Schizosaccharomyces pombe Lindner. Both strains separately exhibit asexual self-flocculation and together, sexual co-flocculation. Flocculation is glucose repressible, but that repression is leaky, because self-flocculation can occur during the late logarithmic phase of growth before either of the C or N sources are depleted.

Microbiology ◽  
2014 ◽  
Vol 160 (6) ◽  
pp. 1063-1074 ◽  
Author(s):  
Matthias Sipiczki ◽  
Anita Balazs ◽  
Aniko Monus ◽  
Laszlo Papp ◽  
Anna Horvath ◽  
...  

The post-cytokinetic separation of cells in cell-walled organisms involves enzymic processes that degrade a specific layer of the division septum and the region of the mother cell wall that edges the septum. In the fission yeast Schizosaccharomyces pombe, the 1,3-α-glucanase Agn1p, originally identified as a mutanase-like glycoside hydrolase family 71 (GH71) enzyme, dissolves the mother cell wall around the septum edge. Our search in the genomes of completely sequenced fungi identified GH71 hydrolases in Basidiomycota, Taphrinomycotina and Pezizomycotina, but not in Saccharomycotina. The most likely Agn1p orthologues in Pezizomycotina species are not mutanases having mutanase-binding domains, but experimentally non-characterized hypothetical proteins that have no carbohydrate-binding domains. The analysis of the GH71 domains corroborated the phylogenetic relationships of the Schizosaccharomyces species determined by previous studies, but suggested a closer relationship to the Basidiomycota proteins than to the Ascomycota proteins. In the Schizosaccharomyces genus, the Agn1p proteins are structurally conserved: their GH71 domains are flanked by N-terminal secretion signals and C-terminal sequences containing the conserved block YNFNAY/HTG. The inactivation of the agn1Sj gene in Schizosaccharomyces japonicus, the only true dimorphic member of the genus, caused a severe cell-separation defect in its yeast phase, but had no effect on the hyphal growth and yeast-to-mycelium transition. It did not affect the mycelium-to-yeast transition either, only delaying the separation of the yeast cells arising from the fragmenting hyphae. The heterologous expression of agn1Sj partially rescued the separation defect of the agn1Δ cells of Schizosaccharomyces pombe. The results presented indicate that the fission yeast Agn1p 1,3-α-glucanases of Schizosaccharomyces japonicus and Schizosaccharomyces pombe share conserved functions in the yeast phase.


1990 ◽  
Vol 110 (5) ◽  
pp. 1617-1621 ◽  
Author(s):  
I M Hagan ◽  
P N Riddle ◽  
J S Hyams

We have used a new cinemicroscopy technique in combination with antitubulin immunofluorescence microscopy to investigate the timing of mitotic events in cells of the fission yeast Schizosaccharomyces pombe having lengths at division between 7 and 60 microns. Wild-type fission yeast cells divide at a length of 14 microns. Separation of daughter nuclei (anaphase B) proceeds at a rate of 1.6 +/- 0.2 microns min-1, until the spindle extends the length of the cell. Coincident with spindle depolymerization, the nuclei reverse direction and take up positions that will become the center of the two daughter cells. This post-mitotic nuclear migration occurs at a rate of 1.4 +/- 0.5 microns-1. In cells in which the weel+ gene is overexpressed fivefold and that have an average length at mitosis of 28 microns, the rate of nuclear separation was only slightly reduced but, as spindles in these cells measure 20-22 microns, the duration of anaphase B was extended by approximately 40%. By contrast, in the mutant weel.50, which divides at 7 microns, both the rate and duration of anaphase B were indistinguishable from wild type. Nuclei reach the ends of these cells earlier but remain there until a point corresponding to the time of postmitotic nuclear migration in wild type. Thus, the events of mitosis can be extended but not abbreviated. These results are discussed in terms of a mitotic termination control that monitors many different events, one of which is spindle elongation.


1989 ◽  
Vol 67 (8) ◽  
pp. 464-467 ◽  
Author(s):  
C. S. Tsai ◽  
Ken P. Mitton ◽  
Byron F. Johnson

The fission yeast Schizosaccharomyces pombe utilizes acetate at subinhibitory concentrations in the presence of D-glucose. The nonionized form of acetate is preferentially utilized, oxidized to 14CO2, and assimilated into lipids and proteins. Acetyl CoA synthetase activity greatly increases in the yeast cells grown in media containing acetate. However, glyoxylate cycle enzymes are not detectable in Schizosaccharomyces pombe. [1-14C] Acetate is incorporated into stereols, sterol esters, neutral lipids, and phospholipids. Assimilation of [1-14C]acetate into the peptide structure of proteins was confirmed by a proteolytic digestion experiment.Key words: acetate utilization, fission yeast, Schizosaccharomyces pombe.


2005 ◽  
Vol 4 (8) ◽  
pp. 1446-1454 ◽  
Author(s):  
Stephanie A. Morris ◽  
Yoichiro Shibata ◽  
Ken-ichi Noma ◽  
Yuko Tsukamoto ◽  
Erin Warren ◽  
...  

ABSTRACT Set2 methylation of histone H3 at lysine 36 (K36) has recently been shown to be associated with RNA polymerase II (Pol II) elongation in Saccharomyces cerevisiae. However, whether this modification is conserved and associated with transcription elongation in other organisms is not known. Here we report the identification and characterization of the Set2 ortholog responsible for K36 methylation in the fission yeast Schizosaccharomyces pombe. We find that similar to the budding yeast enzyme, S. pombe Set2 is also a robust nucleosome-selective H3 methyltransferase that is specific for K36. Deletion of the S. pombe set2 + gene results in complete abolishment of K36 methylation as well as a slow-growth phenotype on plates containing synthetic medium. These results indicate that Set2 is the sole enzyme responsible for this modification in fission yeast and is important for cell growth under stressed conditions. Using the chromatin immunoprecipitation assay, we demonstrate that K36 methylation in S. pombe is associated with the transcribed regions of Pol II-regulated genes and is devoid in regions that are not transcribed by Pol II. Consistent with a role for Set2 in transcription elongation, we find that S. pombe Set2 associates with the hyperphosphorylated form of Pol II and can fully rescue K36 methylation and Pol II interaction in budding yeast cells deleted for Set2. These results, along with our finding that K36 methylation is highly conserved among eukaryotes, imply a conserved role for this modification in the transcription elongation process.


2008 ◽  
Vol 7 (9) ◽  
pp. 1433-1440 ◽  
Author(s):  
Christopher R. Houchens ◽  
Audrey Perreault ◽  
François Bachand ◽  
Thomas J. Kelly

ABSTRACT The initiation of eukaryotic DNA replication is preceded by the assembly of prereplication complexes (pre-RCs) at chromosomal origins of DNA replication. Pre-RC assembly requires the essential DNA replication proteins ORC, Cdc6, and Cdt1 to load the MCM DNA helicase onto chromatin. Saccharomyces cerevisiae Noc3 (ScNoc3), an evolutionarily conserved protein originally implicated in 60S ribosomal subunit trafficking, has been proposed to be an essential regulator of DNA replication that plays a direct role during pre-RC formation in budding yeast. We have cloned Schizosaccharomyces pombe noc3 + (Spnoc3 +), the S. pombe homolog of the budding yeast ScNOC3 gene, and functionally characterized the requirement for the SpNoc3 protein during ribosome biogenesis, cell cycle progression, and DNA replication in fission yeast. We showed that fission yeast SpNoc3 is a functional homolog of budding yeast ScNoc3 that is essential for cell viability and ribosome biogenesis. We also showed that SpNoc3 is required for the normal completion of cell division in fission yeast. However, in contrast to the proposal that ScNoc3 plays an essential role during DNA replication in budding yeast, we demonstrated that fission yeast cells do enter and complete S phase in the absence of SpNoc3, suggesting that SpNoc3 is not essential for DNA replication in fission yeast.


1988 ◽  
Vol 34 (12) ◽  
pp. 1338-1343 ◽  
Author(s):  
Hisao Miyata ◽  
Machiko Miyata ◽  
Byron F. Johnson

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.


2009 ◽  
Vol 75 (9) ◽  
pp. 2765-2774 ◽  
Author(s):  
Esben H. Hansen ◽  
Birger Lindberg Møller ◽  
Gertrud R. Kock ◽  
Camilla M. Bünner ◽  
Charlotte Kristensen ◽  
...  

ABSTRACT Vanillin is one of the world's most important flavor compounds, with a global market of 180 million dollars. Natural vanillin is derived from the cured seed pods of the vanilla orchid (Vanilla planifolia), but most of the world's vanillin is synthesized from petrochemicals or wood pulp lignins. We have established a true de novo biosynthetic pathway for vanillin production from glucose in Schizosaccharomyces pombe, also known as fission yeast or African beer yeast, as well as in baker's yeast, Saccharomyces cerevisiae. Productivities were 65 and 45 mg/liter, after introduction of three and four heterologous genes, respectively. The engineered pathways involve incorporation of 3-dehydroshikimate dehydratase from the dung mold Podospora pauciseta, an aromatic carboxylic acid reductase (ACAR) from a bacterium of the Nocardia genus, and an O-methyltransferase from Homo sapiens. In S. cerevisiae, the ACAR enzyme required activation by phosphopantetheinylation, and this was achieved by coexpression of a Corynebacterium glutamicum phosphopantetheinyl transferase. Prevention of reduction of vanillin to vanillyl alcohol was achieved by knockout of the host alcohol dehydrogenase ADH6. In S. pombe, the biosynthesis was further improved by introduction of an Arabidopsis thaliana family 1 UDP-glycosyltransferase, converting vanillin into vanillin β-d-glucoside, which is not toxic to the yeast cells and thus may be accumulated in larger amounts. These de novo pathways represent the first examples of one-cell microbial generation of these valuable compounds from glucose. S. pombe yeast has not previously been metabolically engineered to produce any valuable, industrially scalable, white biotech commodity.


2007 ◽  
Vol 53 (8) ◽  
pp. 1016-1023 ◽  
Author(s):  
Hye-Won Lim ◽  
Su-Jung Kim ◽  
Eun-Hee Park ◽  
Chang-Jin Lim

A unique gene named pca1+, encoding a metacaspase, was cloned from the fission yeast Schizosaccharomyces pombe and was used to create a recombinant plasmid, pPMC. The metacaspase mRNA level was markedly elevated in the fission yeast cells harboring the plasmid pPMC. Overexpressed Pca1+appeared to stimulate the growth of the fission yeast cells instead of arresting their growth. Its expression was enhanced by stress-inducing agents such as H2O2, sodium nitroprusside, and CdCl2, and it conferred cytoprotection, especially against CdCl2. However, such protection was not reproducible in the budding yeast Saccharomyces cerevisiae harboring pPMC. Taken together, these results propose that Pca1+may be involved in the growth and stress response of the fission yeast.


2002 ◽  
Vol 3 (3) ◽  
pp. 221-225

In recent months a bumper crop of genomes has been completed, including the fission yeast (Schizosaccharomyces pombe) and rice (Oryza sativa). Two large-scale studies ofSaccharomyces cerevisiaeprotein complexes provided a picture of the eukaryotic proteome as a network of complexes. Amongst the other stories of interest was a demonstration that proteomic analysis of blood samples can be used to detect ovarian cancer, perhaps even as early as stage I.


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