Figure 8

ZP and CK expression in ovarian follicles. A) Oocytes in resting primary follicles lack ZP3 expression, but express ZP1, ZP2, and ZP4 [41]. B) ZP3 is expressed in the oocyte of a growing preantral follicle. C) Double color IHC for CK (brown) and ZP (blue) expression in a growing preantral follicle. CK is expressed in granulosa cells (GrC) but no secondary Balbiani body is present in the oocyte. Oocyte surface expresses ZP (blue arrowhead). D) Double color IHC for CK (blue) and ZP (brown) expression in a small antral follicle. CK is expressed in granulosa cells (GrC) and in the oocyte secondary Balbiani body (blue arrowhead). Oocyte surface expresses ZP (orange arrowhead).