Figure 7.
Enhanced CFS induction in cells expressing an ATR-unphosphorylable form of WRN. (A) Average overall chromosome gaps and breaks in WS cells (WS), WS cells expressing an ATR-unphosphorylable form of WRN (WSWRN6A) and in WS cells in which wild-type WRN was reintroduced (WSWRN). Cells were treated with two different doses of Aph for 24 h before harvesting. Data are presented as means of three independent experiments. Error bars represent standard error. (B) Representative Giemsa-stained metaphases of wild-type (WSWRN), WS and WSWRN6A fibroblasts untreated or treated with 0.2 μM Aph. Arrows indicate chromosomal aberrations. (C) Frequency of gaps and breaks at CFS by FISH analysis. Cells were treated as described in (A). FISH was performed using BACs probes corresponding to the FRA3B region. Frequency of fragile site induction is presented as the percentage of chromosome 3 homolog with gaps and breaks at FRA3B. Data are presented as means of three independent experiments. Error bars represent standard error on the mean.