Figure 7.

Cytokeratin staining of serial sections through a 9-week human fetal penis grown for 14 days without hormones. Top, A–C, approximate section levels: Distal (A), mid-shaft (B) and proximal (C) transverse sections stained for K6 and K7. K6 is expressed in the urethral plate and basal cells of the surface epidermis and in basal layers of the urethral groove. K7 is present only in apical layers of the dorsal aspect of the urethral groove) as in non-grafted penile and clitoral specimens (Figs. 4, 8). Bottom, D–F, approximate section levels: Distal (D), mid-shaft (E) and proximal (F) sections through the same xenograft stained with K6 and K10. K6 is expressed as above. K10 is present in apical cells of the surface epidermis, the lateral and ventral aspects of the urethral groove and is absent in the dorsal aspect of the urethral groove as is seen in non-grafted penile and clitoral specimens.

Gross 9.5-week human fetal penile specimen showing approximate levels of post-grafting histologic sections.