Effects of SMG on DNA damage and apoptosis in <i>Rad9</i>^<i>+/+</i> and <i>Rad9</i>^<i>-/-</i> MES cells.

<p>(A) Evaluation of DNA double strand break by neutral comet assay in <i>Rad9</i>^{<b><i>+/+</i></b>} and <i>Rad9</i>^{<b><i>-/-</i></b>} MES cells cultured under 1G or SMG condition. Time points were 1, 2, 3, 4 and 5 days. At least 50 cells for each condition were scored for comet tail moment. (B) Flow cytometric analysis of γ-H2AX formation in <i>Rad9</i>^{<b><i>+/+</i></b>} and <i>Rad9</i>^{<b><i>-/-</i></b>} mMES cells cultured under 1G or SMG condition for 1 or 5 days. (C) Evaluation of DNA damage by alkaline comet assay in <i>Rad9</i>^{<b><i>+/+</i></b>} and <i>Rad9</i>^{<b><i>-/-</i></b>} MES cells cultured under 1G or SMG condition for 1 or 5 days. At least 50 cells for each condition were scored for comet tail moment. (D) Evaluation of DNA damage by alkaline comet assay in <i>Rad9</i>^{<b><i>-/-</i></b>} MES cells with ectopic expression of <i>Rad9</i> (<i>Rad9</i>^{<b><i>-/-</i></b>}<i>+Rad9</i> MES cells) cultured under 1G or SMG condition for 1 or 5 days. At least 50 cells for each condition were scored for comet tail moment. (E) Flow cytometric analysis of <i>Rad9</i>^{<b><i>+/+</i></b>} and <i>Rad9</i>^{<b><i>-/-</i></b>} MES cells cultured under 1G or SMG condition for 1 day to assess apoptosis using Annexin V labeling. Experiments were performed three times and representative analyses are shown (upper). The lower part is the quantitative comparison of apoptosis between the 1G Group and the SMG Group. The data represent mean ± SD of at least three independent experiments. Student’s t test, *P<0.05.