Figure 4

Characterization of the stem/progenitor cell compartment of wt-FVB and RARα1 /KO. (a) Representative histograms of flow cytometry analysis of CD24^low/ALDH^high compartment in mammary epithelium. Primary mammary epithelial cells (approximately1 × 10⁶) were incubated with ALDH substrate with inhibitor (first and third from left upper and lower panels) or without inhibitor (second and fourth from left upper and lower panels) followed by incubation with anti-CD24 Ab and detected with secondary Ab (APC-conjugated) as described in Materials and methods. Inclusion of the DEAB inhibitor reduced the ALDH activity by 82 and 87%, in FVB and RARα1/KO cells, respectively. Gated: CD24^low/ALDH^high (b) Summary of seven individual experiments. Experiments were performed as in A, shown are median, 3.9% and 6.7% respectively, (mean 4.4% and 6.6%, respectively, P = 0.04, unpaired t-test).