A SEROLOGICAL COMPARISON OF VEGETATIVE CELL AND ASCUS WALLS AND THE SPORE COAT OF SACCHAROMYCES CEREVISIAE

1966 ◽  
Vol 12 (3) ◽  
pp. 485-488 ◽  
Author(s):  
I. J. Snider ◽  
J. J. Miller
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Structure ◽  
Vegetative Cell ◽  
Proteolytic Enzyme ◽  
Spore Coat ◽  
Vegetative Cells

Cross-agglutination tests with sera obtained by injection of vegetative cells, asci, and spores into rabbits revealed no immunological distinction between the walls of vegetative cells and asci, whereas the spore coats were found to be serologically distinct from cell and ascus walls. Treatment of vegetative cells and asci with periodate or a proteolytic enzyme before agglutination tests gave results which suggest that the critical antigen is a protein structure.

scholarly journals A Role for MMS4 in the Processing of Recombination Intermediates During Meiosis in Saccharomyces cerevisiae

Genetics ◽  
2001 ◽  
Vol 159 (4) ◽  
pp. 1511-1525 ◽  
Author(s):  
Teresa de los Santos ◽  
Josef Loidl ◽  
Brittany Larkin ◽  
Nancy M Hollingsworth
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Meiotic Recombination ◽  
Biochemical Data ◽  
Dna Metabolism ◽  
Spore Viability ◽  
Vegetative Cells ◽  
Recombination Checkpoint

Abstract The MMS4 gene of Saccharomyces cerevisiae was originally identified due to its sensitivity to MMS in vegetative cells. Subsequent studies have confirmed a role for MMS4 in DNA metabolism of vegetative cells. In addition, mms4 diploids were observed to sporulate poorly. This work demonstrates that the mms4 sporulation defect is due to triggering of the meiotic recombination checkpoint. Genetic, physical, and cytological analyses suggest that MMS4 functions after the single end invasion step of meiotic recombination. In spo13 diploids, red1, but not mek1, is epistatic to mms4 for sporulation and spore viability, suggesting that MMS4 may be required only when homologs are capable of undergoing synapsis. MMS4 and MUS81 are in the same epistasis group for spore viability, consistent with biochemical data that show that the two proteins function in a complex. In contrast, MMS4 functions independently of MSH5 in the production of viable spores. We propose that MMS4 is required for the processing of specific recombination intermediates during meiosis.

Basal Body and Flagellar Development During the Vegetative Cell Cycle and the Sexual Cycle of Chlamydomonas Reinhardii

1974 ◽  
Vol 16 (3) ◽  
pp. 529-556 ◽  
Author(s):  
T. CAVALIER-SMITH
Keyword(s):  
Basal Body ◽  
Vegetative Cell ◽  
Amorphous Material ◽  
Sexual Cycle ◽  
Transitional Region ◽  
Basal Bodies ◽  
Vegetative Cells ◽  
Chlamydomonas Reinhardii ◽  
Body Development ◽  
Microtubular Roots

Basal body development and flagellar regression and growth in the unicellular green alga Chlamydomonas reinhardii were studied by light and electron microscopy during the vegetative cell cycle in synchronous cultures and during the sexual life cycle. Flagella regress by gradual shortening prior to vegetative cell division and also a few hours after cell fusion in the sexual cycle. In vegetative cells basal bodies remain attached to the plasma membrane by their transitional fibres and do not act as centrioles at the spindle poles during division. In zygotes the basal bodies and associated microtubular roots and cross-striated connexions all dissolve, and by 6.5 h after mating all traces of flagellar apparatus and associated structures have disappeared. They remain absent for 6 days throughout zygospore maturation and then are reassembled during zygospore germination, after meiosis has begun. Basal body assembly in developing zygospores occurs close to the plasma membrane (in the absence of pre-existing basal bodies) via an intermediate stage consisting of nine single A-tubules surrounding a central ‘cartwheel’. Assembly is similar in vegetative cells (and occurs prior to cell division), except that new basal bodies are physically attached to old ones by amorphous material. In vegetative cells, amorphous disks, which may possibly be still earlier stages in basal-body development occur in the same location as 9-singlet developing basal bodies. After the 9-singlet structure is formed, B and C fibres are added and the basal body elongates to its mature length. Microtubular roots, striated connexions and flagella are then assembled. Both flagellar regression and growth are gradual and sequential, the transitional region at the base of the flagellum being formed first and broken down last. The presence of amorphous material at the tip of the axoneme of growing and regressing flagella suggests that the axoneme grows or shortens by the sequential assembly or disassembly at its tip. In homogenized cells basal bodies remain firmly attached to each other by their striated connexions. The flagellar transitional region, and parts of the membrane and of the 4 microtubular roots, also remain attached; so also do new developing basal bodies, if present. These structures are well preserved in homogenates and new fine-structural details can be seen. These results are discussed, and lend no support to the idea that basal bodies have genetic continuity. It is suggested that basal body development can be best understood if a distinction is made between the information needed to specify the structure of a basal body and that needed to specify its location and orientation.

Actin During Pollen Germination

1986 ◽  
Vol 86 (1) ◽  
pp. 1-8
Author(s):  
J. HESLOP-HARRISON ◽  
Y. HESLOP-HARRISON ◽  
M. CRESTI ◽  
A. TIEZZI ◽  
F. CIAMPOLINI
Keyword(s):  
Medium Release ◽  
Pollen Tube ◽  
Vegetative Cell ◽  
Pollen Germination ◽  
Pollen Grain ◽  
Actin Microfilaments ◽  
Vegetative Cells ◽  
Stage Of Development ◽  
Angiosperm Species

The cytoplasm of the vegetative cell of the ungerminated pollen grain of Endymton non-scriplus and other angiosperm species contains numerous fusiform bodies sometimes exceeding 15μm in length and 2.5 μm in width, which bind fluorescent-labelled phalloidin and are likely therefore to constitute a storage form of actin. The bodies are dispersed during the activation of the pollen, being replaced by aggregates of slender phalloidin-binding fibrils, which converge towards the germination apertures and are present in the emerging pollen tube. The storage bodies appear to be homologous with crystalline-fibrillar structures, shown in an earlier paper to be abundantly present in the vegetative cells of Nicotiana pollen. These are composed of massive aggregates of linearly disposed units with individual widths of 4–7 nm, probably to be interpreted as actin microfilaments. Vegetative-cell protoplasts from mature but ungerminated pollen disrupted in osmotically balancing medium release extended phalloidin-binding fibrils of a kind not observed in the intact grain. It is suggested that these are derived by the rapid dissociation of the compact actin storage bodies present in the vegetative cell at this stage of development.

scholarly journals DNA demethylation by ROS1a in rice vegetative cells promotes methylation in sperm

2019 ◽  
Vol 116 (19) ◽  
pp. 9652-9657 ◽  
Author(s):  
M. Yvonne Kim ◽  
Akemi Ono ◽  
Stefan Scholten ◽  
Tetsu Kinoshita ◽  
Daniel Zilberman ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Vegetative Cell ◽  
Seed Viability ◽  
Dna Demethylation ◽  
Central Cell ◽  
Dna Glycosylase ◽  
Rice Seed ◽  
Vegetative Cells ◽  
Active Dna Demethylation ◽  
Cell Genome

Epigenetic reprogramming is required for proper regulation of gene expression in eukaryotic organisms. In Arabidopsis, active DNA demethylation is crucial for seed viability, pollen function, and successful reproduction. The DEMETER (DME) DNA glycosylase initiates localized DNA demethylation in vegetative and central cells, so-called companion cells that are adjacent to sperm and egg gametes, respectively. In rice, the central cell genome displays local DNA hypomethylation, suggesting that active DNA demethylation also occurs in rice; however, the enzyme responsible for this process is unknown. One candidate is the rice REPRESSOR OF SILENCING1a (ROS1a) gene, which is related to DME and is essential for rice seed viability and pollen function. Here, we report genome-wide analyses of DNA methylation in wild-type and ros1a mutant sperm and vegetative cells. We find that the rice vegetative cell genome is locally hypomethylated compared with sperm by a process that requires ROS1a activity. We show that many ROS1a target sequences in the vegetative cell are hypomethylated in the rice central cell, suggesting that ROS1a also demethylates the central cell genome. Similar to Arabidopsis, we show that sperm non-CG methylation is indirectly promoted by DNA demethylation in the vegetative cell. These results reveal that DNA glycosylase-mediated DNA demethylation processes are conserved in Arabidopsis and rice, plant species that diverged 150 million years ago. Finally, although global non-CG methylation levels of sperm and egg differ, the maternal and paternal embryo genomes show similar non-CG methylation levels, suggesting that rice gamete genomes undergo dynamic DNA methylation reprogramming after cell fusion.

Translocation of zinc from vacuole to nucleus during yeast meiosis

1983 ◽  
Vol 25 (5) ◽  
pp. 415-419 ◽  
Author(s):  
Carl A. Bilinski ◽  
John J. Miller
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Staining Procedure ◽  
Vegetative Cells ◽  
Nuclear Compartments ◽  
Polyphosphate Bodies ◽  
Yeast Meiosis ◽  
Zinc Translocation

A novel staining procedure employing the UV fluorochrome DAPI (4′,6-diamidino-2-phenylindole∙2HCl) and dithizone (diphenylthiocarbazone) was developed for microcytochemical determination of sites of zinc localization in Saccharomyces cerevisiae Hansen. In vegetative cells vacuolar polyphosphate bodies stained with dithizone, whereas in sporulating cells nucleoli and centriolar plaques were dithizone-positive. Hence, dithizone not only permitted localization of zinc but also indicated zinc translocation from vacuolar to nuclear compartments during differentiation from the vegetative to sporulated state.

Differences in formation of vegetative cells and their walls in Trebouxia and Pseudotrebouxia as further evidence for the classification of these genera

1985 ◽  
Vol 17 (3) ◽  
pp. 281-287 ◽  
Author(s):  
E. Peveling ◽  
J. König
Keyword(s):  
Vegetative Cell ◽  
Cell Walls ◽  
Vegetative Cells

AbstractThe formation of vegetative cells from zoospores and the morphogenesis of the multilayered cell walls during this process was observed in some Trebouxia and Pseudotrebouxia species. In Trebouxia species, e.g. Trebouxia erici, the wall of the vegetative cell is formed around the zoospore while in Pseudotrebouxia species, e.g. Pseudotrebouxia corticola, firstly an autosporangium with its wall is formed then the autosporangium further divides.

Presence of endotoxin in vegetative cells of Bacillus thuringiensis var. sotto

1970 ◽  
Vol 16 (9) ◽  
pp. 905-906 ◽  
Author(s):  
P. Luthy ◽  
Y. Hayashi ◽  
T. A. Angus
Keyword(s):  
Bacillus Thuringiensis ◽  
Vegetative Cell ◽  
Vegetative Cells ◽  
Cell Extracts

Endotoxin was found in vegetative cell extracts of Bacillus thuringiensis var. sotto. The distribution of the toxin in fractions obtained by centrifugation at different speeds indicates an association with cell particles, most likely membranes.

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