Figure 2
From: Origin of germ cells and formation of new primary follicles in adult human ovaries
Formation of ovarian SE from TA mesenchymal precursors. A) Tunica albuginea (ta) fibroblasts (fb) showing strong CK immunoexpression (brown color). One cell in mesenchymal-epithelial transition is apparent at the surface (fb/se). B) Ovarian stroma (os) shows no CK staining of fibroblasts (fb). C) Fibroblasts associated with the TA surface exhibit mesenchymal-epithelial transitory forms (D). E) Appearance of SE cells (se) is associated with a diminution of CK immunoexpression (-fb). F) Differentiation of the SE is associated with a diminution of cellularity in adjacent TA. Bar in (B), for (A-E). Cytokeratin 18 immunostaining, hematoxylin counterstain.