Dot1-Dependent Histone H3K79 Methylation Promotes the Formation of Meiotic Double-Strand Breaks in the Absence of Histone H3K4 Methylation in Budding Yeast
Figure 1
Dot1 plays a meiotic role in the absence of Set1.
(A) Schematic representation of events during meiosis. (B, C) Spore viability of various strains was measured by dissecting spores. Spores were incubated at 30°C for 3 days. Each bar indicates percentage of spore viability and actual number of total dissected tetrads (parenthesis). Distribution of viable spores per tetrad is shown in (C). Wild type, NKY1303/1543; set1 mutant, MBY015/016; dot1 mutant, MBY005/006; set1 dot1 double mutant, MBY037/039. (D) Meiotic cell division I was analyzed by DAPI staining of wild type (blue circles; NKY1303/1543), dot1 (green circles; MBY005/006), set1 (purple triangles; MBY005/006 and set1 dot1 (red triangle; MBY037/039) mutant cells. At least 150 cells were counted by DAPI staining for each time point. Plotted values are the mean values with standard deviation (S.D.) from four independent time courses. (E) Expression of various meiotic proteins was verified by western blotting. At each time point, cells were fixed with TCA and cell lysates were subject to the analysis. Representative images are shown. Phosphorylated species of Zip1, Hop1, Rec8, and Clb1 are shown by arrows. Wild type, NKY1303/1543; set1, MBY015/016; dot1, MBY005/006; set1 dot1 double mutant, MBY037/039.