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. Author manuscript; available in PMC: 2010 Mar 6.
Published in final edited form as: Cell. 2009 Mar 6;136(5):852–864. doi: 10.1016/j.cell.2009.01.017

Figure 5. Extending mitosis alters origin efficiencies across the genome.

Figure 5

A) Left: FACS analysis of cells synchronized using cdc25-22 and released into MBC shows only a small susbset of cells entering S after 70 minutes. Right: ChIP of Orp1 from MBC-treated cells. Orp1 accumulates at ori2004, ori2060, and ars727 and remains bound during MBC treatment. B) Representative regions from array analyses showing reduction in the usage of early-firing efficient origins in cells treated with MBC and released into HU. MBC-treated and HU control cells are represented by black and gray lines, respectively. Asterisks mark reproducible decreases in three experiments. C) A subset of inefficient regions show increased BrdU incorporation after MBC treatment. Asterisks mark reproducible increases. D) Relative origin usage in MBC-treated samples and HU controls. BrdU IPs were assayed by qPCR. Bars represent the ratio of signal in MBC-treated to HU control samples, and a region that does not replicate in HU-treated cells was used for normalization. Values are averaged from three experiments, and error bars show the standard deviation. (i) The five efficient origins tested display reduced signals in the MBC samples. (ii) Eight low-efficiency regions, labeled by chromosome, show reproducible increases in replication after MBC treatment. (D) Origin efficiencies following MBC treatment. Replication efficiency was determined using qPCR of genomic DNA from both MBC-treated and HU-control cells. Values are averaged from three experiments.