Gene expression data for the budding yeast mutants pol30-8, dot1Δ and pol30-8 dot1Δ

ABSTRACT: The mutation in the budding yeast gene PCNA, pol30-8, as well as deletion of DOT1 (dot1Δ), encoding the only histone H3 K79 methyltransferase in budding yeast, have been implicated in telomeric silencing. To further analyze these mutants, we used microarrays to study whether either pol30-8, dot1Δ or the double mutant leads to changes in gene expression levels when compared to isogenic wild-type strains. ABSTRACT: Telomere-associated position effect variegation (TPEV) in budding yeast has been used as a model for understanding epigenetic inheritance and gene silencing. A widely used assay to identify mutants with improper TPEV employs the URA3 gene at the telomere of chromosome VII-L that can be counter-selected with 5-fluoroorotic acid (5-FOA). 5-FOA resistance has been inferred to represent lack of transcription of URA3 and therefore to represent heterochromatin-induced gene silencing. For two genes implicated in telomere silencing, POL30 and DOT1, we show that the URA3 telomere reporter assay does not reflect their role in heterochromatin formation. Rather, an imbalance in ribonucleotide reductase (RNR), which is induced by 5-FOA, and the specific promoter of URA3 fused to ADH4 at telomere VII-L are jointly responsible for the variegated phenotype. We conclude that metabolic changes caused by the drug employed and certain mutants being studied are incompatible with the use of certain prototrophic markers for TPEV. 3 replicates each of the S. cerevisiae MATalpha wild-type, pol30-8, dot1Δ and pol30-8 dot1Δ strains carrying the epigenetic silencing reporter genes hmr::ADE2 and URA3-VIIL (in the W303 genetic background; the ade2-1 and ura3-1 alleles normally present in this background were deleted) were grown to mid-logarithmic phase and harvested for RNA extraction and hybridization on Affymetrix microarrays.

ORGANISM(S): Saccharomyces cerevisiae

SUBMITTER: Bruce Stillman 

PROVIDER: E-GEOD-27222 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress