Figure 2.

p38α Regulates Luminal Progenitor Cell Maintenance

(A) Colonies formed in Matrigel by EpCAM^highCD49f^med luminal cells isolated from virgin females of the indicated genotypes were quantified and values are expressed as percentage to the numbers in control MMTV-Cre mice (n = 3 independent experiments). ^∗∗p ≤ 0.005.

(B) Luminal cells (EpCAM^highCD49f^med) separated as indicated in Figure 1B were further analyzed by FACS according to CD61 and CD49f expression. The histogram shows the quantification of the CD61⁺CD49f⁺ luminal progenitor cells (n = 5 animals). ^∗∗p ≤ 0.005.

(C) Relative expression of the p38α mRNA in CD61⁺ and CD61⁻ cell populations separated as in (B) from MMTV-Cre mice was determined by qRT-PCR. The expression level in CD61⁺ cells was given the value of 1.

(D) Relative expression of the p38α mRNA in CD61⁺ and CD61⁻ cell populations separated as in (B) from the indicated mice was determined by qRT-PCR (n = 3 animals). The expression levels in cells from MMTV-Cre mice were given the value of 1. ^∗∗p ≤ 0.005.

(E) ALDH1A3 staining for alveolar progenitor cells in virgin females of the indicated genotypes (n = 3 animals). Arrowheads indicate ALDH1A3⁺ cells. Scale bars, 20 μm. Quantifications are shown in the histogram. ns, not significant.

(F) Analysis of cell death by TUNEL staining in mice of the indicated genotypes, either virgin or during early pregnancy (n = 3 animals). Arrowheads indicate apoptotic cells. Scale bars, 50 μm. Quantifications during early pregnancy are shown in the histogram. ^∗∗p ≤ 0.005.

See also Figure S2.