FIG 2.
Cyclin ET74A T393A hematopoietic stem and progenitor cells show proliferative defects in response to hematologic stress. (A) Absolute numbers of HSCs in wild-type and cyclin ET74A T393A mice were enumerated at steady state. Inset, steady-state HSC cell cycle distributions were determined using intracellular Ki67 and Hoechst 33342 staining. (B) Assay of BrdU label-retaining cells was performed as previously described (1). Percentage of BrdU+ HSCs after 10 days of labeling in vivo and percentage of BrdU label-retaining HSCs after 70 days of chase are shown. Shown are means ± standard errors of the means of results for three mice per time point. (C and D) HSC numbers and cell cycle distributions (insets) were determined 10 days and 21 days after 5FU treatment. (E and F) Absolute numbers of the indicated multipotent progenitor cell populations (MPP1- to -3) in wild-type and cyclin ET74A T393A mice were enumerated at steady state and 21 days following 5FU treatment. *, P < 0.05; **, P < 0.02, using Student's t test.