Fig. 2. Mec1 focus formation requires Ddc2, but not Mec1 or Rad53, kinase activity. (A) Myc-Mec1 localisation after HO induction for 0 and 4 hours in JKM179 derivatives deleted for both ddc2 and sml1 (GA1825) or for sml1 alone (GA1817). IF was performed with anti-Myc (9E10; green) and with affinity-purified anti-Sir4 (red) antibodies. Values correspond to the percentage of nuclei exhibiting a single bright Mec1 focus above a low background of diffuse Mec1. (B) Myc-Mec1 ChIP assay was performed as described in Fig. 1D using JKM179 derivatives carrying deletions for ddc2 sml1 or sml1 alone. (C) Myc-Mec1 localisation in JKM179-derived strains carrying deletions for sml1, for sml1 and rad53 together, or for sml1 with Myc-mec1-kd1 or Myc-mec1-kd2 mutations. IF for Myc-Mec1 (green, 9E10) and anti-pore (red, Mab414) is shown and the percentage of nuclei with one bright Mec1 focus is given. To the right, a JKM179 derivative expressing Myc-Rad53 was analysed by anti-Myc IF (green) after cut induction. Bars, 1 µm.