Fig. 4. hta1 mutants arrest at G₂–M. Exponentially growing cells were synchronized in G₁ with α–factor and released at 13°C. Samples were taken at the times indicated and analyzed. Strains used were: HTA1 (FY605), hta1–200 (FY1817) and hta1–300 (FY1818). (A) Cell growth in YPD. (B) DNA content by flow cytometry. (C) Quantitation of the nuclear and bud morphology. UB, unbudded; SB, small budded; LB, large budded; DB, double budded. The same cells were used for flow cytometric analysis in (B).