Fig. 4
From: Loss of Calponin 2 causes premature ovarian insufficiency in mice
Morphology of atretic follicles and MOFs. A An example of ovarian section from an 8 weeks old homozygous Cnn2-KO mouse shows atretic follicles containing collapsed oocytes with only empty zona pellucida remaining (→). B An example of a WT mouse ovarian section shows atretic follicles containing dark red-stained oocytes (➤). C & D The example sections show multi-oocyte follicles at different stage of development, from primordial follicle (➤) and secondary follicles (→). A and B are H&E staining, and C and D are PAS staining images. E ZP-3 expression in the zona pellucida of a normal preantral follicle (half arrow) of WT mouse. F ZP3 expression in zona pellucida of a multi-oocyte follicle (arrowhead) and degenerated follicles (arrow) of Cnn2-KO mouse. The oocytes with irregular shaped or collapsed zona pellucida indicate oocyte degenerations. G FSHR was expressed in the granulosa cells and oocytes of antral follicles as well as in the corpus luteum of Cnn2-KO mouse. H VASA was expressed in oocytes in primordial, primary, secondary and antral follicles of Cnn2-KO mouse