Figure 1
From: Epithelial–mesenchymal transformation and apoptosis in rat urethra development
Gross images of genital tubercle at different embryonic stages under SEM. Ventral view of embryonic genital tubercle on ED 15 (a), ED 16 (b), and ED 18 (c) under SEM. Tail and lower limbs were removed. With progression of embryonic time, elongation of the genital tubercle, deepening of the urethral groove, and emergence of coronary sulcus can be seen. Magnified views of the urethral groove area (marked with a dotted line rectangle in the upper panels) are presented in the respective lower panels (d–f). Urethral groove appears as a complete structure with no signs of a canal inside it. CS, coronary sulcus; ED, embryonic day; PF, preputial fold; SEM, scanning electron microscope; UG, urethral groove.
