Fig. 2. Ctnnb1 deletion from late-stage mouse UGE impairs prostatic bud formation but not KRT14⁺ mature UGS basal epithelium formation.

Male Shh^+/+;Ctnnb1^{tm2Kem/tm2Kem} (control) and Shh^creERT2/+;Ctnnb1^{tm2Kem/tm2Kem} (Ctnnb1^iLOF) embryos were exposed to tamoxifen and progesterone as described. (A–B) E18.5 male UGSs were stained by ISH to visualize Nkx3-1 (purple) and counterstained by IHC to visualize UGE marked by CDH1. Blue arrowheads indicate ventral prostatic buds, red arrowheads are anterior prostatic buds and green arrowheads are dorsolateral prostatic buds. (C) Nkx3-1⁺ bud numbers are mean ± SE of five independent samples per group from at least three litters. Asterisks indicate significant differences from controls (p < 0.05). (D–G) Near mid-sagittal sections from three UGSs per genotype UGS sections were immunofluorescently labeled to visualize CTNNB1, CDH1 and KRT14. Cell nuclei are stained with DAPI (blue). Arrowheads indicate prostatic buds. The arrow in panel E (inset) indicates a representative CTNNB1 immunonegative cell. Abbreviations are bl: bladder, sv: seminal vesicle.