Fig. 5

Photomicrograph of the sheep ovary during the follicular phase. A Ovarian cortex showing preovulatory follicles (POF) and regressed corpus luteum (RCL). B Ovarian cortex showing two large antral follicles (LAF1 & LAF2) surrounded by the same theca folliculi (TF) and connected by zona garnulosa with the same basement membrane (arrows). C Ovarian cortex showing atretic antral follicles (AAF) with thickening in the PAS positive follicular basement membrane (arrow) and zona pellucida (arrowhead). D The wall of preovulatory follicles showing dissociated granulosa cells (G), thin interrupted PAS positive follicular basement membrane (arrow), theca interna (TI) and theca externa (TE) with proliferation of fibroblasts (arrowhead). E Showing atretic antral follicle with hyalinization of the follicular basement membrane (BM), proliferation of theca interna cells (TI) and angiogenesis (BV). Note the central region contained few apoptotic granulosa cells (AG) and eliminated oocyte. F Showing regressed corpus luteum with autophagic lutein cells (ALC); some had PAS positive material (star) and degeneration of blood vessels with thick PAS positive endothelial basement membrane (BV). Original magnification; A: X12.5, scale bar = 1mm, B & C: X40, scale bar = 500 µm, D-F: X200, scale bar = 100 µm, PAS & Hx