Rpd3 and Sin3 delay activation of late-firing replication origins. Wild-type (OAy618), rpd3Δ (OAy781), and sin3Δ (JAy44) cells were synchronized in late G1 with α-factor at 23°C and released into S phase at 18°C. At the indicated intervals, cells were fixed for analysis. (A) DNA Polɛ association with early (ARS607 and ARS1) and late (ARS603, ARS1413, and ARS501) replication origins was analyzed by ChIP. Origin-specific PCR analysis of immunoprecipitated (Precipitates) and total (Input) DNA is shown. (B) Quantification of the data shown in panel A plotted as the percent bound. (C) DNA content of cells was analyzed by FACScan. (D) The percentage of budded cells was determined by microscopic analysis of at least 100 cells at each time point.