Dot1-Dependent Histone H3K79 Methylation Promotes the Formation of Meiotic Double-Strand Breaks in the Absence of Histone H3K4 Methylation in Budding Yeast
Figure 3
Dot1 promotes Rad51-focus formation in the absence of Set1.
(A) Immunostaining analysis of Rad51 (green) and Dmc1 (red) for wild type (NKY1303/1543), dot1 (MBY005/006), set1 (MBY015/016) and set1 dot1 (MBY037/039) mutant strains was carried out. The bar indicates 2 µm. (B) Kinetics of Rad51 (left) or Dmc1 (right)-focus positive cells in various strains. A focus-positive cell was defined as a cell with more than 5 foci. More than 100 nuclei were counted at each time point. The symbols represent the wild type (blue circles; NKY1303/1543), dot1 mutant (green circles; MBY005/006), set1 mutant (purple triangles; MBY015/016), and set1 dot1 mutant (red triangle; MBY037/039). (C) A number of foci of Rad51 were counted in different strains. The symbols represent the wild type (blue circles; NKY1303/1543), dot1 mutant (green circles; MBY005/006), set1 mutant (purple triangles; MBY015/016), and set1 dot1 mutant (red triangle; MBY037/039). The average number of foci per positive nucleus with S.D. is shown on top. (D) Immunostaining analysis of Rad51 (green) for the dmc1 mutant (MBY009/010), dmc1 dot1 mutant (MBY003/004), dmc1 set1 mutant MBY021/022), and dmc1 set1 dot1 mutant (MBY282/285) was carried out. The bar indicates 2 µm. (E) Meiotic cell division I was analyzed by DAPI staining of the dmc1 mutant (blue circles; MBY009/010), dmc1 dot1 mutant (green circles; MBY003/004), dmc1 set1 mutant (purple triangles; MBY021/022), and dmc1 set1 dot1 mutant (red triangle; MBY282/285) cells. At least 150 cells were counted by DAPI staining for each time point. (F) Kinetics of Rad51-focus positive cells in the dmc1 mutant (blue circles; MBY009/010), dmc1 dot1 mutant (green circles; MBY003/004), dmc1 set1 mutant (purple triangles; MBY021/022), and dmc1 set1 dot1 mutant (red triangle; MBY282/285) strains. A focus-positive cell was defined as a cell with more than 5 foci. More than 100 nuclei were counted at each time point. (G) The number of Rad51 foci was counted in different strains as described above. The average numbers of foci per a Rad51-foci positive nucleus with S.D. is shown on top.