Fig. 2

Loss of SIM2s increases the incidence of aberrations associated with stalled replication forks. a Representative images of DNA combing assays demonstrating the indicated conditions. Scale bar, 2 μm. b DNA fiber tracts isolated from MCF7 cells that were treated as in Fig. 1a were assessed for the presence of gaps between IdU and CldU tracts. A significant increase in gap length was observed in cells containing shSIM2, with no difference found between no treatment and HU treatment groups. Values indicate the median with the interquartile range. Whiskers span 5-95th percentile; n ≥ 100 strands. Student’s t test was performed to test significance. c Finally, shSIM2 containing cells had lower incidence of actively elongating tracts, with a significant increase in stalled forks and newly firing origins. Likelihood ratio and Pearson’s chi-squared tests were performed to test correlations; n ≥ 100 strands. *p value < 0.05