Figure 10

Mitogen-activated protein kinase immunoexpression (brown color) in dividing and differentiating germ cells. Symmetrically dividing putative germ cells dashed line, panel A) in the TA (ta) showed strong nuclear MAPK immunostaining dotted lines. The cells showed an increase in size in the upper cortex (uc, panel B). Further increase in size of putative germ cells was detected during vascular transport, and accompanied by an appearance of focal cytoplasmic MAPK immunoexpression (c, panel C). D) During assembly with CK+epithelial nest (see brown color, serial section in panel E), the oocytes exhibited strong MAPK immunostaining of both the nuclear (dotted line) and cytoplasmic regions. In freshly formed primary follicles (F, see panel G for low power magnification of D and F), the MAPK heavily stained cytoplasmic clusters (c) were apparent, except an isolated paranuclear (Balbiani) body (dashed line). Strong nuclear staining (dotted line) persisted. MAPK (A-D, F and G) and CK single color immunohistochemistry (G), with hematoxylin counterstain. "s" arrow in (G) points to the distant ovarian surface.