Figure 1.

Generation of S O D1^−/− cells expressing human SOD1 from the tet-off promoter. (a) Schematic representation of the generation of DT40 S O D1^−/− + hSOD1 cells. (b) Schematic representation of the SOD1 genomic locus and configuration of the targeted locus. (c) Southern blot analysis for the confirmation of the status of the SOD1 wild-type (WT), WT + human SOD1 (+/+), heterozygous (+/−), and homozygous (−/−) cells, using NdeI digested genomic DNA and the probe indicated in (b). (d) Dox-dependent disappearance of human SOD1, as confirmed by western blot analysis, with α-tubulin used as the loading control. (e) Growth curves of indicated genotype cells. Indicated mutant cells were cultured in the presence or absence of 1 μg/mL Dox. Dox had no effect on the growth or viability of wild-type cells.