Figure 4: Genome instability in Sprtn KO MEFs.
From: Spartan deficiency causes genomic instability and progeroid phenotypes
(a) Images showing chromatin bridges (arrows) and micronuclei (arrowheads) in SprtnF/− MEFs treated with MeOH or 4-OHT for 48 h. DNA was visualized by DAPI staining. (b) Quantitation of chromatin bridges. Experiments were performed as in a. At least 300 cells were scored for chromatin bridges and percentages of positive cells are shown. Three independent experiments were performed and mean±s.d. is shown. ****P<0.0001 (two-tailed unpaired t-test). (c) Quantitation of micronuclei-containing cells. Experiments were performed as in a. ****P<0.0001 (two-tailed unpaired t-test). (d) Formation of 53BP1 nuclear bodies. SprtnF/− MEFs were treated with MeOH or 4-OHT for 48 h. At least 300 cells were scored for 53BP1 nuclear bodies and percentages of nuclei with different number of 53BP1 nuclear bodies per nucleus are shown. (e) Chromosomal abnormalities in Sprtn KO cells. SprtnF/− MEFs were treated with MeOH or 4-OHT for 48 h. Twelve hours after completion of the treatments, mitotic spreads were prepared and examined by microscopy. Representative pictures of mitotic spreads are shown in the left panel. Arrows indicate some of the chromosome abnormalities. In the right panel, representative images of chromosome gaps in Sprtn KO MEFs are indicated by arrowheads. (f) Quantitation of abnormal chromosomes. Cells harbouring chromosomal abnormalities were scored in 50 mitotic spreads of SprtnF/− MEFs treated with MeOH or 4-OHT.
