Fig. 4

Hyperacetylation prolongs S-phase duration in total, substages and at sex chromosomes. a Exemplary images of S-patterns were depicted to illustrate the categorization into S-phase substages. Microtus cabrerae cells were transiently transfected with a plasmid encoding PCNA (either RFP or GFP-tagged) and either GFP-macroH2A1 or DsRed-HP1 beta. Cells were treated with DMSO or LBH-589 according to the protocol in the Additional file 4A and analyzed by live-cell imaging. In HDACi-treated cells, the total S-phase duration is significantly increased. Early S-phase duration increased from 3.4 up to 5.1 h, as well as mid-S-phase, which is prolonged by approximately 1 h. Sample sizes are indicated on the left-hand side. Statistical significance was tested using the t test, comparing the total S-phase duration and S-phase substage duration in untreated and treated samples. Standard deviations of replicates are shown in the boxes. **P < 0.01. b The duration of X chromosome replication was estimated out of live-cell imaging data. The duration of H3K27me3 decorated X* and H3K9me3 decorated X replication is significantly increased. The length of X* replication is prolonged from 1.9 up to 2.7 h and the length of X duplication from 1.8 h up to 2.2 h. Standard deviations of replicates are shown next to the numbers in the boxes. Statistical significance was tested using the t test, comparing the duration of replication of X* and X in untreated and treated samples. ***P < 0.001