Figure 1

Electrophoresis patterns of MNase-digested DNA of Δpcf1 mutant and wild type cells, their sensitivity to hydroxyurea (HU) and genetic interactions between cds1⁺and pcf1⁺. (A, B) Agarose-gel electrophoresis patterns of DNA prepared from enzyme-digested chromatin of wild type and Δpcf1 mutant (A) and clr6-1 mutant (B) cells. Note the early appearance of smaller DNA fragments, corresponding to nucleosomes, from digested chromatin of both Δpcf1 and clr6-1 mutants relative to that of the wild type. (C) Sensitivity of wild type and Δpcf1 mutant cells to HU. Both cells grew similarly on the plates without HU regardless of its dilution, whereas Δpcf1 mutant cells grew slowly relative to wild type cells on plates amended with 6 mM HU. (D) Growth of wild type, Δpcf1 and Δcds1 mutant cells harboring the empty vector (Vec), pREP-cds1⁺, or pREP-pcf1⁺ in the presence or absence of thiamine. For a detailed comparison of the growth of these cells, see the text.