Figure 5 : Chromatin is more accessible to MNase following DNA damage in set2Δ cells and less accessible in gcn5Δ cells.

From: A histone H3K36 chromatin switch coordinates DNA double-strand break repair pathway choice

Figure 5

(a,b) Mid-log phase cells were incubated in 3 μg ml−1 bleocin for 1 h followed by MNase digestion for 10 min at the indicated concentrations. Digested chromatin DNA was resolved by gel electrophoresis and detected by ethidium bromide staining. The gels are representative of three independent repeats. (c) MNase digested chromatin DNA resolved on agarose gels were analyzed using Image J. The proportion of low molecular weight DNA (<tetranucleosome) was calculated as a percentage of the total sample. set2Δ cells have a significantly higher proportion of low molecular weight particles following digestion with 15U MNase (P=0.032; t-test), while gcn5Δ cells have a significantly lower population of low molecular weight particles when compared with wild type (P=0.037; t-test), indicating an increase in set2Δ and a decrease in gcn5Δ chromatin accessibility. Data are the mean of at least three independent repeats and error bars (±s.e.) are shown (* denotes P<0.05; t-test). (d) Control MNase digestions (no bleocin treatment) were analysed as described for c. Data are the mean of at least three independent repeats and error bars (±s.e.) are shown. Comparison of set2Δ and gcn5Δ samples with wild-type revealed no significant change in the proportion of low molecular weight particles (P-value cutoff 0.05; t-test).