Fig. 5. No mature luminal cells in Foxa1^–/– prostate. (A-D) EM analysis on 12-week-old rescued Foxa1^+/+ and Foxa1^–/– VPs. Scale bars: 2 µm in A,B; 500 nm in C,D. Asterisks indicate the lumen. Wild-type cells (A,C) contain secretory materials seen in apical vesicles (arrow) and at luminal surface (arrowhead). Secretory material was absent in Foxa1^–/– cells (B,D). (E) MALDI-MS protein profiles of m/z range 3000-16,000 obtained from 4-week-old rescued Foxa1^+/+, Foxa1^+/– and Foxa1^–/– prostates. Continuous profiles were zoomed in at m/z range 16,100-26,000. Arrows indicate peaks that were absent in Foxa1^–/– but present in control prostates. (F) RT-PCR for Pbsn and Sbp. Bs, basement membrane.