Electron microscopy of germinating ascospores ofSaccharomyces cerevisiae

Rij, N.J.W. Kreger-van

doi:10.1007/bf00689354

Cited by 45 publications

(28 citation statements)

References 6 publications

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“…It is a well-known fact in electron microscopical studies on the ascospore of Saccharomyces yeast that it is surrounded with a wall composed of two or three layers, i.e., outer electron-dense, middle less-dense and inner dense (11,16). This result shows four zones included in two main layers, OS and IS, in the spore wall.…”

Section: Discussionmentioning

confidence: 99%

“…The functions of mitochondria during the sporulation or germination processes have been elucidated by HALVORSON and his collaborators (1,2). In addition, the germination process has been analysed from many other standpoints, especially physiologically and biochemically, e.g., the effects of carbon sources (3-S), gaseous conditions (4, 6, 7), respiration and changes in the spore components and enzymatic activities (6,8,9), and also the stainability and morphology with the freeze-etching method or scanning electron microscopy, etc (9)(10)(11).…”

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confidence: 99%

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Morphological changes in ascospores of Saccharomyces cerevisiae during aerobic and anaerobic germination.

Sando

Oguchi

Nagano

et al. 1980

J. Gen. Appl. Microbiol.

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The stainability of ascospores and vegetative cells of Saccharomyces cerevisiae to acid-fast staining, using hot Ziehl's carbolic fuchsin solution, 5 % sulfuric acid, and diluted Lofer's methylene blue, was examined. Resting spores and growing haploid cells (a type strain 24428 and a type 3626) retained much fuchsin dye in the cells. Only mature spores of diploid G2-2 resisted methylene blue staining. The stainability of Mycobacterium phlei IFO 3158 also examined. The kinetics of germinationn were examined. The loss of the stainability with acid-fuchsin and of the resistance to methylene blue was used as a criterion of germination. The ascospores germinated anaerobically as well as aerobically. Especially in the early stage of germination, there was found no difference in the germination rates under both conditions. Ultrastructure of germinating ascospores cultured in aerobic and anaerobic conditions was examined by ultrathin sectioning and electron microscopy. At the first stage of germination, the ascospores swelled in aerobic as well as anaerobic cultures. The outer spore coat and the outer zone of inner spore wall disappeared during the germination process, the inner zone of the spore wall then giving rise to a germinated spore cell wall (=extruded germ tube wall). The vacuole became granular. The mitochondria showed no change in shape and number in aerobic cultures, but seemed to swell and disintegrate in the later stages of anaerobic germination.

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Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Morphological changes in ascospores of Saccharomyces cerevisiae during aerobic and anaerobic germination.

Sando

Oguchi

Nagano

et al. 1980

J. Gen. Appl. Microbiol.

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“…Spore wall components are then deposited between this double membrane (Lynn and Magee 1970). Electron microscopic analysis of the mature spore wall reveals four layers (Kreger-van Rij 1978). The two inner layers, consisting mainly of glucans and mannans, are similar in composition to the vegetative cell wall and often appear as a single layer (Katohda et al 1984;Briza et al 1988).…”

Section: Rme1 Ime1 and Ime2mentioning

confidence: 99%

Isolation of two developmentally regulated genes involved in spore wall maturation in Saccharomyces cerevisiae.

Briza¹,

Breitenbach²,

Ellinger³

et al. 1990

Genes Dev.

198

233

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During sporulation of Saccharomyces cerevisiae, the four haploid nuclei generated by meiosis are encapsulated within multilayered spore walls. Taking advantage of the natural fluorescence imparted to yeast spores by the presence of a dityrosine-containing macromolecule in the spore wall, we identified and cloned two genes, termed DIT1 and DIT2, which are required for spore wall maturation. Mutation of these genes has no effect on the efficiency of spore formation or spore viability. The mutant spores, however, fail to accumulate the spore wall-specific dityrosine and lack the outermost layer of the spore wall. The absence of this cross-linked surface layer reduces the resistance of the spores to lyric enzymes, to ether, and to elevated temperature. Expression of the DIT and DIT2 genes is restricted to sporulating cells, with the DIT1 transcripts accumulating at the time of prospore enclosure and just prior to the time of dityrosine biosynthesis. Both genes act in a sporeautonomous manner implying that at least some of the activities responsible for forming the outermost layer of the spore wall reside within the developing spore rather than in the surrounding ascal cytoplasm. As the DIT2 gene product has significant homology with cytochrome P-450s, DIT2 may be responsible for catalyzing the oxidation of tyrosine residues in the formation of dityrosine.

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“…The four major components of the spore wall are arranged in layers formed consecutively, beginning with the innermost layer and working outward (Tachikawa et al, 2001). The two inner layers consist primarily of mannan and 1,3-b-glucan and are similar to the vegetative cell wall (Kreger-Van Rij, 1978). The two outer layers of the spore wall are unique to the spore and confer on the spore much of its resistance to environmental damage (Smits et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

Interspore bridges: a new feature of the Saccharomyces cerevisiae spore wall

Coluccio

Neiman

2004

Microbiology

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The Saccharomyces cerevisiae spore wall is a multilaminar coat that surrounds individual spores and protects them from environmental insult. Scanning electron microscopy reveals that the four spores of an ascus are connected by interspore bridges. Transmission electron microscopy of spores indicates that these bridges are continuous with the outer layers of the spore wall. In chs3 mutants, which lack the chitosan and dityrosine layers of the spore wall, bridges are absent. By contrast, in dit1 mutants, which lack only the dityrosine layer, bridges are present, suggesting that the bridges may be composed of chitosan. Interspore bridges are shown to be necessary to hold spores together after release from the ascus. A function for these bridges in the maintenance of heterozygous markers in a homothallic yeast population is proposed.

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Electron microscopy of germinating ascospores ofSaccharomyces cerevisiae

Cited by 45 publications

References 6 publications

Morphological changes in ascospores of Saccharomyces cerevisiae during aerobic and anaerobic germination.

Morphological changes in ascospores of Saccharomyces cerevisiae during aerobic and anaerobic germination.

Isolation of two developmentally regulated genes involved in spore wall maturation in Saccharomyces cerevisiae.

Interspore bridges: a new feature of the Saccharomyces cerevisiae spore wall

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