Figure 2.

Characterization of Somatic Testicular Niche Cells in the TOs by Immunofluorescent Staining of Whole Mounts

Double staining for STAR/3βHSD (top row), ACTA2/COL1 (middle row), and SOX9/ZO1 (bottom row) applied to scaffold-based (left and middle columns) and scaffold-free (right column) adult TOs (n = 3 TOs derived from different donors per staining). Representative photographs of TOs following short-term (left column) and long-term (middle and right columns) culture are shown. Steroidogenic Leydig cells (white arrows) stained positive for both STAR (green) and 3βHSD (purple), PTMCs (white/red arrows) stained for ACTA2 (green), scaffold (^∗) and COL1-producing cells (red arrows) stained for COL1 (purple), COL1-producing PTMCs (white arrow) stained for both ACTA and COL1, and tight-junction protein-producing Sertoli cells (white arrow) stained for both SOX9 (green) and ZO1 (purple). Cell nuclei were stained blue with DAPI. The inserts depict several z stacks at low magnification merged with maximum intensity projection to give an overview. See also Figure S1 and Table S1.