Fig. 5

SUT457 regulates the levels of telomeric ssDNA by acting in trans. a Schematic illustration indicating the presence of endogenous (endogSUT457, light grey box) and ectopic SUT457 (ectopSUT457, dark grey box) in wild-type and sut457Δ strains. The level of SUT457 expression for each constructed strain is indicated on the right: + (wild-type levels of expression), +++ (higher expression than wild-type), and – (no expression). Arrows indicate the direction of SUT457 transcription at each locus. b Analysis of telomeric ssDNA levels in wild-type (lane 1), wild-type [ectopSUT457] (lane 2), sut457Δ (lane 3), and sut457Δ [ectopSUT457] (lane 4) strains at passage 5. Genomic DNA was extracted, fragmented with XhoI and subjected to native southern blotting using a biotinylated probe against telomeric repeats (left panel). The southern blot was then treated with 0.4 N NaOH and the denatured DNA was re-probed to monitor equal loading (right panel). c Telomeric ssDNA levels were analysed in five independent clones of the indicated wild-type and mutant strains at passage 5. The ssDNA signal for each strain detected in the native southern blot was normalised to the corresponding signal in the denatured southern blot. Error bars represent standard error of the mean. * P < 0.05; n/s, not significant. Statistical analysis was performed using one-way ANOVA (Dunnett’s test)