Fig. 2

Transmission electron microscopy of the ovary at the RUD stage; a connective tissue showing several fibroblasts with elliptic nuclei and heterochromatin accumulated to the nuclear envelope; b collagen fibers among fibroblasts (white arrow); c oogonia with mitochondria and polyribosomes in the cytoplasm and nuclei at the different meiosis stages. Note the pairing of the chromosomes (white arrows); d synaptonemic complex (white arrow); e follicular cell with elliptical nucleus, electron-dense basal lamina and cytoplasm filled by mitochondria. Oocyte and follicular cell microvilli poorly developed (black arrow); f oocyte with large nucleus, with heterochromatin granules dispersed throughout the nucleoplasm (black arrows) and rounded nucleolus; g cytoplasm with many polyribosomes and mitochondria. Note the electron-dense granules in the perinuclear region (black arrow); h detail of the electron-dense granules or nuage; i–k cytoplasm with many mitochondria and dilated rough endoplasmic reticulum, with the presence of granular material of different electron densities (black arrows); l The Golgi complex receives materials from transitional vesicles that are electron-lucid on the cis face (white arrow) and releases vesicles with granular electron-dense material on the trans face (black arrow). F fibroblast, FC follicular cell, G Golgi complex, L basal lamina, M mitochondria, N nucleus, NU nucleolus, RER rough endoplasmic reticulum