Fig. 1. Genetic interactions between plo1+, components of PBF and M-G1 transcription. (A) Synthetic defective cell separation phenotypes revealed by double mutants in plo1, fkh2, sep1 and mbx1. Cells containing combinatorial mutants of fkh2
, sep1
, mbx1
and plo1-ts35 were grown on solid YE medium at 25°C, and viewed with DIC optics. Scale bar, 5 µm. (B) Effect on transcription of genes expressed at M-G1 phase by overexpressing mutant versions of Plo1p. Cells containing either pREP1: plo1+ (wild-type), pREP1: plo1DHK625AAA [Polo-box domain (PBD) mutant], or pREP1: plo1K69R [kinase domain (KD) mutant] were grown to mid-exponential stage before the removal of thiamine to induce overexpression. After 16 hours cells were removed for microscopic examination and northern blot analysis of cdc15+, spo12+ and plo1+ mRNA levels. Quantification of each transcript against rRNA is shown. Scale bar, 5 µm.