Screen for factors affecting lifespan during quiescence in fission yeast
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ABSTRACT: Identification of novel genetic factors that control chronological lifespan in Schizosaccharomyces pombe during long term nitrogen starvation in a competitive environment
Project description:Identification of novel genetic factors that control chronological lifespan in Schizosaccharomyces pombe during long term nitrogen starvation in a competitive environment
Project description:Identification of novel genetic factors that control chronological lifespan in Schizosaccharomyces pombe during long term nitrogen starvation in a competitive environment
Project description:Glucose as a source of energy is centrally important to our understanding of life. We investigated the cell division-quiescence behavior of the fission yeast Schizosaccharomyces pombe under a wide range of glucose concentrations (0-111 mM). The mode of S. pombe cell division under a microfluidic perfusion system was surprisingly normal under highly diluted glucose concentrations (5.6 mM, 1/20 of the standard medium, within human blood sugar levels). Division became stochastic, accompanied by a curious division-timing inheritance, in 2.2-4.4 mM glucose. A critical transition from division to quiescence occurred within a narrow range of concentrations (2.2-1.7 mM). Under starvation (1.1 mM) conditions, cells were mostly quiescent and only a small population of cells divided. Under fasting (0 mM) conditions, division was immediately arrested with a short chronological lifespan (16 h). When cells were first glucose starved prior to fasting, they possessed a substantially extended lifespan (∼14 days). We employed a quantitative metabolomic approach for S. pombe cell extracts, and identified specific metabolites (e.g. biotin, trehalose, ergothioneine, S-adenosyl methionine and CDP-choline), which increased or decreased at different glucose concentrations, whereas nucleotide triphosphates, such as ATP, maintained high concentrations even under starvation. Under starvation, the level of S-adenosyl methionine increased sharply, accompanied by an increase in methylated amino acids and nucleotides. Under fasting, cells rapidly lost antioxidant and energy compounds, such as glutathione and ATP, but, in fasting cells after starvation, these and other metabolites ensuring longevity remained abundant. Glucose-starved cells became resistant to 40 mM H(2)O(2) as a result of the accumulation of antioxidant compounds.
Project description:This RNA-Seq analysis compares gene expression of the pho7∆ fission yeast (Schizosaccharomyces pombe) strain prior to phosphate starvation (0 HR), i.e. in phosphate replete conditions, and at various times after phosphate starvation (4, 8, 12, 24, 36, and 48 HR) contrasting to the WT fission yeast S. pombe cells grown in phosphate replete conditions (WT 0HR)
Project description:This RNA-Seq analysis compares gene expression of fission yeast (Schizosaccharomyces pombe) strains prior to phosphate starvation (0 HR) and at various times after phosphate starvation (4, 8, 12, 24, 36, and 48 HR) contrasting to the WT fission yeast S. pombe cells grown in phosphate replete conditions (WT 0HR)
Project description:This RNA-Seq analysis compares gene expression of fission yeast cells (Schizosaccharomyces pombe) at various times after phosphate starvation (2, 4, and 8 HR) either with 100 µg/ml cycloheximide or without drug contrasting to the cells grown in phosphate replete conditions (0HR) in the absence of the drug.
Project description:Target of rapamycin complex 1 (TORC1) is implicated in growth control and aging from yeast to humans. Fission yeast is emerging as a popular model organism to study TOR signaling, although rapamycin has been thought to not affect cell growth in this organism. Here we analyzed the effects of rapamycin and caffeine, singly and combined, on multiple cellular processes in fission yeast. The two drugs led to diverse and specific phenotypes that depended on TORC1 signaling pathway inhibition, including prolonged chronological lifespan, inhibition of global translation, inhibition of cell growth and division, and reprogramming of global gene expression mimicking nitrogen starvation. Rapamycin and caffeine differentially affected these various TORC1-dependent processes. Combined drug treatment augmented most phenotypes and effectively blocked cell growth. Although rapamycin showed a much more subtle effect on global translation than did caffeine, rapamycin was more effective in prolonging chronological lifespan. Rapamycin prolonged the lifespan of non-growing cells only when applied during the growth phase but not when applied after cells had stopped proliferation. The doses of rapamycin and caffeine strongly correlated with growth inhibition and with lifespan extension. This comprehensive analysis will inform future studies into TORC1 function and cellular aging in fission yeast and beyond.
Project description:RNA-seq analysis compares gene expression of the ecl3∆ and ecl123∆ mutants to the wild-type fission yeast (Schizosaccharomyces pombe).
Project description:This RNA-Seq analysis compares gene expression of the wild-type fission yeast (Schizosaccharomyces pombe) strain at various times after transfer to defined phosphate-replete ePMGT(+PO4) medium (2, 4, 8 HR) contrasting to the WT fission yeast S. pombe cells grown in phosphate-replete YES medium (0HR).