Loss of Srf does not induce persistent changes in stem and progenitor cell cycle. (A) BrdU incorporation following a 24 hours in vivo pulse in Srf^+/+;Mx1-Cre and Srf^{Δ/Δ;Mx1-Cre} mice. Cell cycle indices (G0-G1 and S) of BM LSKs, LT-HSCs, ST-HSCs, MPPs, and MPs are shown for each genotype at 5 (top) and 35 (bottom) days after pIpC injection (n = 4 mice per genotype *P < .05 by Mann-Whitney test). Box-and-whisker plots show medians, quartiles, highest and lowest values. (B) In vitro growth of LSKs isolated from Srf^+/+;Mx1-Cre and Srf^{Δ/Δ;Mx1-Cre} mice 35 days after pIpC treatment. Values shown are mean ± SEM (n = 3 per genotype). (C) qRT-PCR analysis of cell-cycle regulators expression in Srf^{Δ/Δ;Mx1-Cre} LSKs. Expression levels were normalized to Gapdh, and results were expressed relative to the level of expression measured in Srf^+/+;Mx1-Cre LSKs (set to 1). Values shown are mean ± SEM from 3 independent experiments.