Fig. 2. Induction of p63 expression by vaginal mesenchyme. UtE and VgE isolated from newborn (A-D) or adult (2-months-old, E and F) BALB/c mice were recombined with newborn UtM or VgM. The tissue recombinants were grown as renal grafts in nude mice for 4 weeks. When newborn VgE (A) or UtE (C) was recombined with UtM, the epithelium was p63-negative and columnar. By contrast, when newborn UtE (B) or VgE (D) was recombined with VgM, epithelium was p63-positive and squamous. Thus, mesenchyme determines expression of p63 in the newborn UtE and VgE. However, the original expression of p63 in adult-VgE (positive) (E) and UtE (negative) (F) was not altered by heterotypic mesenchyme.