Research Paper Volume 9, Issue 12 pp 2587—2609

Mitogen-activated protein kinases, Fus3 and Kss1, regulate chronological lifespan in yeast

Figure 3. Cells lacking FUS3 or KSS1 exhibit increased stress resistance. (A) Indicated yeast strains were patched onto YPD agar plates, grown for 2 days and then flooded with iodine to detect relative glycogen accumulation (observed as reddish-brown staining of the yeast patch; (see Materials and Methods). A representative of three independent experiments is shown. (B) Quantitative comparison of glycogen accumulation shown in A. Images of replicate stained plates were quantified by densitometry. Error bars represent the standard deviation across 3 independent experiments. (C) Qualitative spot assay of 3-day old cultures grown in SD medium with 2% glucose (left panel), and exposed to 100 mM H2O2 for 30 min (middle panel) or to high temperature (55oC) for 10 min (right panel). Higher survival (growth) of the mutant strains relative to wild type BY4742 (WT) indicates that cells lacking the indicated MAPKs exhibit different degrees of increased stress tolerance.