Fig. 3.
Ultrastructure of mature (metaphase II stage) oocytes retrieved after superovulation treatment or natural ovulation.
Transmission electron microscope was employed for monitoring morphologic analysis. Micrograph A (natural ovulation) and B (superovulation) show multivesicular bodies. Micrograph C (natural ovulation) and D (superovulation) show the morphology and distribution of cortical granules, microvilli and smooth endoplasmic reticulum. L: lipid; M: Mitochondria; MVB: Multivesicular body; ZP: Zona pellucida; CG: Cortical granule; MV: Microvilli; PVS: Perivitelline space; SER: smooth endoplasmic reticulum; ZP: Zona pellucida. Magnification = ×6,000 (A), ×8,000 (B) and ×25,000 (C, D). Scale bars=2 μm (A, B) and 1 μm (C, D).