Figure 3.

(A) Cell cycle regulation of DRC1. Cultures of wild-type (Y300) cells were synchronized with α-factor and released into YPD at 30°C. Samples for RNA isolation were collected at 10 min, and Northern blot analysis was performed by using DRC1, RNR1, and ACT1 as probes. (B and C) drc1–1 mutants are defective in DNA synthesis at the restrictive temperature. Cells from both W303 ρ⁰ (wild type) (Y794) and an isogenic drc1–1 derivative (Y795) were arrested with α-factor at 24°C, then shifted to 37°C for 1 hr before releasing from the α-factor block into YPD at 37°C. Aliquots were removed at 30 min intervals for analysis of the budding profile (B) and DNA content by FACS (C).