Figure 8

Triple color immunohistochemistry for vascular route of the oocyte-nest assembly. Immunostaining CK/ZP/EN with CK18 (brown color), HSPZ (blue color), and endothelial CD31 – third sequence visualized with VIP(purple color). A) Medullary vessels show strong CD31 immunostaining (arrowhead), contrasting weak immunoexpression in cortical vessels (B). C) in the area adjacent to (B) (arched arrow) the vascular "pocket" (vp) shows adjacent endothelial cells, CK+ nest walls (w), and a ZP+ intermediate segment of the oocyte (o). Panels D and E show vascular wall (red arrowhead) with a lumen (vl) containing ZP+ oocyte "caught" by CK+ extensions (yellow arrowheads) from the nest wall (w). ft, follicle top of an adjacent primary follicle. No hematoxylin counterstain.