Unknown,Transcriptomics,Genomics,Proteomics

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Early stages of yeast senescent cells

ABSTRACT: We performed transcriptional and metabolic profiling for yeast at early stages of senescence (4th, 7th and 11th generation), that is, for populations in which most cells are still alive. Transcriptional profiles showed up- and down-regulation for about 20% of the genes profiled after the first 4 generations, few further changes by the 7th generation, and an additional 12% of the genes were up- and down-regulated after 11 generations. Pathway analysis revealed that these 11th generation cells had accumulated transcripts coding for enzymes involved in sugar metabolism, the tricarboxylic acid (TCA) cycle and amino acid degradation, and showed decreased levels of mRNAs coding for enzymes involved in amino acid biosynthetic pathways. Stationary phase-induced genes were highly expressed after 11 generations even though the growth medium contained adequate levels of nutrients, indicating deterioration of the nutrient sensing and/or signaling pathways by the 11th generation. These changes are presumably early indications of replicative senescence. Cells of yeast strain BY4742 were labeled with biotin and cultivated in YPD medium at 30M-BM-0C. The labeled cells at early stages of senescence (4th, 7th and 11th generation) were isolated using Dynabeads Biotin Binder (Invitrogen, Carlsbad, CA, USA). Total RNA samples were prepared from the senescent cells. Antisense RNA was synthesized and labeled with Cy3 for the 4th, 7th, and 11th generation and with Cy5 for the 1st generation. Each mixture of Cy3- and Cy5-labeled antisense RNA was hybridized on a 3D-Gene Yeast Oligo Chip 6K (Toray, Kanagawa, Japan). The hybridized array was scanned with a 3D-Gene Scanner 3000 (Toray).

ORGANISM(S): Saccharomyces cerevisiae

SUBMITTER: Yukio Mukai

PROVIDER: E-GEOD-59797 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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