FIP200 deletion depletes fetal HSCs. (A) Cell numbers in E14.5 and E18.5 fetal livers of control and CKO mice. n = 5-13, ^#P < .01. Data are mean ± SE (B) Representative FACS analysis of fetal liver cells from E14.5 control and CKO embryos. HSCs were gated as CD150⁺CD48⁻Lin⁻Mac1⁺Sca1⁺ cells. (C-D) The frequency (C) and number (D) of fetal HSCs in control and CKO embryos shown in panel B.