Figure 5: Effects of Sprtn KO on DNA replication forks.
From: Spartan deficiency causes genomic instability and progeroid phenotypes
(a) Schematic representation of DNA fiber assays. MEFs were treated with MeOH or 4-OHT for 48 h and sequentially labelled with IdU and CldU to mark ongoing replication. A picture of a representative replication track is shown. At least 100 fibres were scored for each sample in all of the DNA fiber experiments. (b) A box plot showing distribution of the lengths of CldU tracts in SprtnF/− MEFs treated with MeOH or 4-OHT for 48 h. NS, not significant (P=0.829, two-tailed unpaired t-test). (c) Effect of ultraviolet irradiation on replication forks. DNA fiber assays were performed with SprtnF/− MEFs with or without ultraviolet irradiation (40 J m−2) between IdU and CldU labelling. Distribution of replication forks at different CldU/IdU ratios is shown. (d–f) Effect of ultraviolet irradiation on replication forks. Experiments were performed as in c using SprtnF/F; Cre-ERT2 MEFs (K3) expressing wild-type human Spartan or the E112A mutant (d), wild-type human Spartan, the PIP* or the UBZ* mutant (e), and wild-type mouse Spartan or the SHP* mutant (f). Horizontal red lines in c–f indicate median values.
