Irradiation and 5-FU treatment promote cellular transition of LSK to LSK⁻ cells.

<p>(<b>A</b>) Lethal irradiation causes an increase in the percentage of apoptotic LSK⁻ cells. Mice were treated by two split doses of 550-cGy gamma irradiation (separated by 3 hours), and the apoptotic cells (7AAD⁺Annexin V⁺) in the LSK⁻ population were analyzed by FACS at different time points (n = 4). **: <i>p</i><0.01. (<b>B</b>) Total number and percentages of LSK and LSK⁻ cells in bone marrow of lethally irradiated WT mice were determined at different time points (n = 4). *: <i>p</i><0.05; **: <i>p</i><0.01. (<b>C</b>) Total number and percentages of LSK and LSK⁻ in bone marrow of 5-FU treated WT mice at different time points. The mice were treated with 5-FU (200 mg/kg) by intravenous injection, and the percentages of LSK and LSK⁻ cells were monitored at different time points (n = 4). *: <i>p</i><0.05; **: <i>p</i><0.01. (<b>D</b>) The apoptotic rate of LSK⁻ cells in 5-FU treated mice. WT mice were treated with 5-FU, and apoptotic rate of LSK⁻ cells were monitored at different time points (n = 4). *: <i>p</i><0.05; **: <i>p</i><0.01.