Figure 2. Ablation of β1 integrin does not affect prostate tissue maintenance, but perturbs epithelial cell population numbers and differentiation in androgen-rescued castrated mice.

a) H&E staining of 26 wk old Itgβ1^fl/fl;WT and Itgβ1^fl/fl;Cre prostates reveal no gross morphological differences between the genotypes. Scale bar, 50 μm. b) Schematic representation of the timeline used for castration, and subsequent testosterone supplementation. c) p63 immuno-staining of dorsal prostates reveal an up-regulation of the number of basal epithelial (p63-positive, arrowheads) cells in Itgβ1^fl/fl;Cre animals. Scale bar, 25 μm. d) Quantitation of the number of p63- stained cells per acinus was performed, and is represented as a percentage of total epithelial cells. * p<0.0001. e) Immuno-staining using anti-Mist1 antibodies reveals almost all luminal epithelial cells to be strongly stained in Itgβ1^fl/fl;WT tissue (arrows), whereas in Itgβ1^fl/fl;Cre samples, a number of luminal cells have low/absent staining (arrowheads), possibly indicating a delay or defect in differentiation caused by loss of β1 integrin. f) Quantitation of Mist1 staining in Itgb1^fl/fl;WT (dark boxes) and Itgβ1^fl/fl;Cre animals (white boxes). Cells were judged to be positive (high and low) or negative for Mist1 staining. *p<0.0001 Scale bar, 25 μm.