Protein Synthesis in Relation to Sporulation and Meiosis in Yeast

Section: Fig 4 (A)mentioning

confidence: 99%

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confidence: 99%

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confidence: 99%

See 1 more Smart Citation

Two-dimensional protein patterns during growth and sporulation in Saccharomyces cerevisiae

Trew¹,

Friesen²,

Møens³

1979

“…Appearance of cycloheximide resistance in sporulating cultures of API. Cycloheximide resistance during sporulation can manifest itself either as the ability to complete the sporulation process in the presence of the drug (13) or as the ability to give rise to colony-forming units in cycloheximide-containing medium. We determined the stage at which the process of ascus formation becomes insensitive to cycloheximide in the following way.…”

Section: Resultsmentioning

confidence: 99%

Timing of ribosome synthesis during ascosporogenesis of yeast cells: evidence for early function of haploid daughter genomes

Emanuel¹,

Magee²

1981

During meiosis and sporulation in Saccharomyces cerevisiae, the recessive genetic marker for cycloheximide resistance, believed to be due to an altered ribosomal protein (C. S. McLaughlin, in M. Nomura et al., ed., Ribosomes, Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y.), is expressed as early as meiosis II. Ribosomal ribonucleic acid synthesis peaks near the time that cycloheximide resistance begins to appear. Less than 25% of the 17S and 25S ribonucleic acid of the vegetative cells persists in spores, but pulselabeling studies indicate that >90% of the stable ribonucleic acid made after 6 h survives in spores. These results indicate that the haploid daughter genomes begin to function near the time of meiosis II. 1342 on August 5, 2020 by guest

“…Glycogen accumulates only after sporulation has been initiated by cell transfer to acetate; eventually, the acetate can be removed, and glycogen be used as a carbon source (15,16). A carbon source is needed to maintain ATP (2) and to allow the synthesis of new macromolecules needed for meiosis and sporulation; some new proteins made during sporulation on potassium acetate have been identified (18,20). Other necessary precursors, including nitrogenand phosphate-containing compounds, are usually available inside the cells during sporulation on acetate.…”

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confidence: 99%

Initiation of Yeast Sporulation by Partial Carbon, Nitrogen, or Phosphate Deprivation

Chu

Freese

1982

In this paper we show that partial deprivation of a carbon source, a nitrogen source, or phosphate in the presence of all other nutrients needed for growth initiates meiosis and sporulation of Saccharomyces cerevisiae homothallic strain Y55. For carbon deprivation experiments, cells were grown in synthetic medium (pH 5.5) containing an excess of one carbon source and then transferred to the same medium containing different concentrations of the same carbon source. In the case of transfer to different acetate concentrations, the log optical density at 600 nm increased at the previous rate until the cells had used up all of the acetate, whereupon the cells entered a stationary phase and did not sporulate. The same was observed with ethanol. In contrast, at different concentrations of dihydroxy-acetone or pyruvate, cells grew at different rates and sporulated optimally at intermediate concentrations (50 to 75 mM). The response to galactose was similar but reflected the presence of a low-affinity galactose transport system and the induction of a high-affinity galactose transport system. Cells could also sporulate when a glucose medium ran out of glucose, apparently because they initiated sporulation during the subsequent lag period and then used the produced ethanol as a carbon source. For phosphate deprivation experiments, cells growing with excess ethanol or pyruvate and phosphate were transferred to the same medium containing limiting amounts of phosphate. First, they used up the intracellular phosphate reserves for rapid growth, and then they sporulated optimally when an intermediate concentration (30 μM) of phosphate had been added to the medium. For nitrogen deprivation experiments, cells grown with excess acetate, ethanol, or pyruvate and NH 4 + were transferred to the same medium from which all nitrogen had been removed. These cells sporulated well in acetate medium but poorly in ethanol and pyruvate media. However, the sporulation frequency in the latter media could be increased greatly by adding intermediate concentrations (1 mM) of the slowly metabolizable amino acids glycine, histidine, or phenylalanine. If one assumes that the sporulation response to partial deprivation of carbon-, nitrogen-, or phosphorus-containing compounds reflects control by a single metabolite, the intracellular concentration of this metabolite may decide at the START position (G1 phase) of the cell cycle whether a /α cells enter mitosis or meiosis.