[en] At the antral follicle stage, the nucleolus is entirely composed of a homogeneous proteinic compact mass. This nucleolar compaction during oogenesis seems to be a general feature in mammalian oocytes. However, when oocyte maturation is induced by gonadotropin hormone (LH), oocytes enter into preovulatory stage. All the nucleoli are vacuolated and extranucleolar bodies appear in the germinal vesicle near the nucleolar mass. Based on the results obtained by ultrastructural cytochemical stainings, we postulate that these extranucleolar bodies originate from the nucleolar mass itself. The presence of the extranucleolar bodies could reflect the extrusion of nucleolar material, essentially ribonucleoproteins, into the ooplasm. This material could persist after fertilization in the pronuclei until the resumption of transcription at the early stage of embryogenesis.
Antoine, Lepoint, Baeckeland, Goessens (1987) Evolution of the rat oocyte nucleolus during follicular growth. Biology of the Cell 107-112.
Antoine, Lepoint, Baeckeland, Goessens (1988) Ultrastructural cytochemistry of the nucleolus in rat oocytes at the end of the folliculogenesis. Histochemistry 89:221-226.
Azevedo, Castilho, Coimbra (1984) Fine structure and cytochemistry of the oocyte nucleolus in the mollusc Helcion pellucidus (Prosobranchia). J. Ultrastruct. Res. 89:1-11.
Baeckeland, Antoine, Lepoint, Goessens (1986) Etude des vacuoles nucléolaires observées dans les ovocytes de rat. Bull. Assoc. Anat. 70:5-8.
Bernhard (1969) A new staining procedure for electron microscopical cytology. J. Ultrastruct. Res. 27:250-265.
Bertout (1984) Ultrastructural cytochemistry of NOR in oocytes of Nereis diversicolor (Annelia, Polychaeta). Biol. Cell 52:35-42.
Buys, Osinga (1980) Abundance of protein-bound sulfhydryl and disulfide groups at chromosomal nucleolus organizing regions. Chromosoma 77:1-11.
Chouinard (1971) A light and electron microscope study of the nucleolus during growth of the oocyte in the prepubertal mouse. J. Cell Sci. 9:637-663.
Chouinard (1973) An electron microscope study of the extranucleolar bodies during growth of the oocyte in the prepubertal mouse. J. Cell Sci. 12:55-69.
Coimbra, Azevedo (1984) Structure and evolution of the nucleolus during oogenesis. Ultrastructure of Reproduction, J. Van Blerkown, P.M. Motta, Martinus Nijhoff Inc, The Hague; .
Crozet, Motlik, Szollosi (1981) Nucleolar fine structure and RNA synthesis in porcine oocytes during the early stages of antrum formation. Biol. Cell 41:35-42.
Crozet, Kanka, Motlik, Fulka (1986) Nucleolar fine structure and RNA synthesis in bovine oocytes from antral follicles. Gamete Res. 14:65-73.
Hartung, Keeling, Patel, Bobrow, Stahl (1983) Nucleoli, micronucleoli and nucleolus-like structures in human oocytes at meiotic prophase I studied by the silver—NOR technique. Cytogenet. Cell Genet. 35:2-8.
Motlik, Kopecny, Travnik, Pivko (1984) RNA synthesis in pig follicular oocytes. Autoradiographic and cytochemical study. Biol. Cell 50:229-236.
Pedersen, Peters (1968) Proposal for a classification of oocytes and follicles in the mouse ovary. J. Reprod. Fertil. 17:555-557.
Pennel, Bell (1985) The use of gold—labelled ribonuclease as probe for RNA in nuclear bodies and cytoplasmic inclusions in plant cells. Eur. J. Cell Biol. 38:181-184.
Ploton, Bendayan, Adnet (1983) Ultrastructural localization of Ag—NOR proteins and nucleic acids in reticulated nucleoli. Biol. Cell 49:29-34.
Schultz, Hermo, Leblond (1984) Structure, development and cytochemical properties of the nucleolus—associated ⪡Round Body⪢ in rat spermatocytes and early spermatids. Am. J. Anat. 171:41-57.
Sheridan, Barnett (1969) Cytochemical studies on chromosome ultrastructure. J. Ultrastruct. Res. 27:216-229.
Takeuchi (1984) Electron microscopic study of silver staining of nucleoli in growing oocytes of rat ovaries. Cell Tiss. Res. 236:249-255.
Takeuchi (1986) Ethanol-phosphotungstic acid staining of basic proteins in the nucleolar condensation occurring in growing mouse oocytes. J. Electron Microsc. 35:173-184.
Takeuchi (1987) Electron microscopic study on the bismuth staining of nucleoli in growing mouse oocytes. Acta Histochemica et Cytochemica 20:295-304.
Thiry (1988) Study of RNA distribution in the nucleolar components of Ehrlich cell using RNase—gold method. Histochemistry 89:231-236.
Wassef, Burglen, Bernhard (1979) A new method of vizualization of preribosomal granules in the nucleolus after acetylation. Biol. Cell 34:153-158.
