Summary
The cumulus cell mass enclosing a penetrated human egg was studied. The egg, recovered from the Fallopian tube approximately 80 h after luteinizing hormone peak and 35 h after insemination, was surrounded by a large, expanded and dissociated cumulus. Dispersions of the outermost cumulus cell layers occurred during processing, the innermost cell layers remained attached enclosing the egg.
The photomicrographs showed that the follicular cells were embedded in an intercellular matrix and contact via gap-junction-like structures between neighboring cells existed. Cumulus cell processes traversing the zona pellucida were not found. Two types of follicular cells coexisted within the cumulus, light and dark cells. These cellular types, were different in morphology and size. Light cells displayed cytoplasmic organelles normally associated with protein synthesis and steroidogenesis. Dark cells with long cytoplasmic processes were involved in sperm phagocytosis. It is suggested from the characteristics of the cytoplasmic organclles that dark cells seem to be modified light follicular cells.
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References
Anderson E, Beams HW (1960) Cytological observations on the fine structure of the Guinea pig ovary with special reference to the oogonium primary oocyte and associated follicle cells. J Ultrastruct Res 3: 432–446
Bedford JM (1972) An electron microscopic study of sperm penetration into the rabbit egg after natural mating. Am J Anat 133: 213–254
Björkman N (1962) A study of the ultrastructure of the granulosa cells of the rat ovary. Acta Anat 51: 125–147
Blandau RJ (1980) In vitro fertilization and embryo transfer. Fertil Steril 33: 3–11
Gwatkin RBL, Anderson DF, Hutchinson CF (1972) Capacitation of hamster spermatozoa in vitro: The role of cumulus components. J Reprod Fertil 30: 389–394
Lopata A, Brown JB, Leeton JF, Talbot JMc, Wood C (1978) In vitro fertilization of preovulatory oocytes and embryo transfer in infertile patients treated with clomiphene and human chorionic gonadotropin. Fertil Steril 30: 27–35
Motta P, Takeva Z, Palermo D (1971) On the presence of cilia in different cells of the mammalian ovary. Acta Anat 78: 591–603
Moyer DL, Kunitake GM, Nakamura RM (1965) Electron microscopic observation on phagocytosis of rabbit spermatozoa in the female genital tract. Experientia 21: 6–7
Ortiz ME, Croxatto HB (1979) Observations on the transport, aging and development of ova in the human genital tract. In: Talwar GP (ed) Recent advances in reproduction and regulationof fertility, pp 307–317
Pereda J, Coppo M (1980) Spermiophagy by cumulus cells of tubal human oocytes. Arch Biol Med Exper 13: 96
Pereda J, Croxatto HB (1977) Ultrastructure of human eggs. 2nd International Congress of Human Reproduction. Tel Aviv, Israel. October
Reynolds ES (1963) The use of citrate at high pH as an electronopaque stain in electron microscopy. J Cell Biol 17: 208–212
Soupart P, Strong AP (1974) Ultrastructural observations on human oocytes fertilized in vitro. Fertil Steril 25: 11–43
Suzuki S, Kitai H, Tojo R, Seki K, Oba M, Fijiwara T, Iizuka R (1981) Ultrastructure and some biologic properties of human oocytes and granulosa cells cultured in vitro. Fertil Steril 35: 142–148
Szöllösi D (1976) La phagocytose des spermatozoides par les cellules du cumulus oophorus de follicules de Veau en culture. C R Acad Sc Paris 283 Série D: 801–804
Szöllösi D, Hunter RHF (1973) Ultrastructural aspects of fertilization in the domestic pig: sperm penetration and pronucleus formation. J Anat 116: 181–206
Tesarík J, Dvorák M (1982) Human cumulus oophorus preovulatory development. J Ultrastruct res 78: 60–72
Thompson RS, Moore-Smith D, Zamboni L (1974) Fertilization of mouse ova in vitro: An electron microscopic study. Fertil Steril 25: 222–249
Zamboni L (1970) Ultrastructure of mammalian oocytes and ova. Biol Reprod Suppl 2: 44–63
Zamboni L, Mishell DR, Bell JH, Baca M (1966) Fine structure of the human ovum in the pronuclear stage. J Cell Biol 30: 579–599
Zamboni L, Moore-Smith D, Thompson RS (1972) Migration of follicle cells through the zona pellucida and their sequestration by human oocytes in vitro. J Exp Zool 181: 319–340
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Pereda, J., Coppo, M. Ultrastructure of the cumulus cell mass surrounding a human egg in the pronuclear stage. Anat Embryol 170, 107–112 (1984). https://doi.org/10.1007/BF00319465
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DOI: https://doi.org/10.1007/BF00319465