Figure 2. A unique basal progenitor population (p63+ KRT7+) maintains the transitional epithelium at the SCJ.
a, The transitional epithelium containing basal progenitors (p63+ KRT7+ KRT8−, arrowheads) is located between the stratified squamous and simple columnar cardia epithelium. n=11. b, The transitional basal cells serve as progenitors for the transitional epithelium as shown by lineage tracing with the p63-CreER and Krt7-CreER alleles. n=3. c, Schematic depicts culture of the transitional basal progenitor cells. d, Distinct epithelium reconstituted by p63+KRT7− and p63+KRT7+ basal progenitors in air-liquid interface (ALI) culture. Note the thick keratin layer (star) and Loricrin+ cells are not present in the epithelium reconstituted by the transitional basal progenitors. n=5 per group. e, Diagram shows the transitional basal progenitor cells (p63+ KRT7+) and luminal cells (KRT7+) in the transitional epithelium. Scale bar, 20 μm.