Flow cytometric analysis of hematopoietic progenitors of Msi2^Gt/Gt mice. (A) Histogram showing total number of nucleated cells in hind limbs of wild-type (Msi2^+/+) and Msi2^Gt/Gt mice for young (2-5 months, n = 6) and old mice (> 12 months, n = 6). (B) FACS profiles of WT and Msi2^Gt/Gt LSK subsets in 3.5-month-old animals. (C) Numbers of WT and Msi2^Gt/Gt LSK cells in young and old mice (n = 6 for each). (D-K) Frequency of LT-HSCs, ST-HSCs, LMPPs, CLPs, CMPs, GMPs, and MEPs of young and old WT and Msi2^Gt/Gt mice. Six mice were studied for the primitive progenitors of each group, 4 for the intermediate progenitors in young mice and 5 in old mice. Black bars show cells derived from WT, and white bars are cells from Msi2^Gt/Gt mice. Error bars indicate SEM. *P < .05; **P < .005.