Figure 3.

Ultrastructure images of t0 ((a), (b)) and t1 ((c), (d)) ovarian cortical tissue. A primordial follicle with a layer of flattened granulosa cells. The oocyte nucleus shows homogeneous euchromatin surrounded by the nuclear membrane. Cytoplasm is well organized with perinuclear round mitochondria (a). Spindle stromal cells with moderately dispersed chromatin and homogeneous cytoplasm (b). A primary follicle with a layer of cuboidal granulosa cell firmly attached to the oocyte. The oocyte nucleus has a slight irregular outline and euchromatin content. Mitochondria are eccentrically placed at one side of the oocyte cytoplasm (c). Stromal cells have moderately dispersed chromatin, compact cytoplasm with enlarged mitochondria (d). t0 = fresh tissue and t1 = vitrified/warmed tissue.