Summary
After cultivation in a modified Trowell-system (organ ciilture) oocytes of 12- to 40-day-old rats were studied under the light and electron microscope. The cultivation period was 72 hrs. Egg cells from primary and early secondary follicles which are characterized by the lack of a zona pellucida and by one or at most two very large Golgi's complexes located near the nucleus do not show any alterations. The other egg cells are characterized by membrane packages which can otherwise only be observed in mature egg cells right before or after the ovulation. Meiotic processes or the formation of polar bodies are only seldom to be seen. These egg cells are surrounded by a thick zona pellucida. From these findings the following conclusions can be drawn:
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1.
In organ cultures meiotic processes are prevented by the inhibitory influence of follicle cells (Foote and Thibault, 1969).
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2.
A cytoplasmic maturation proceeds independently.
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3.
In-vivo an inhibitory factor influences the cytoplasmic maturation. This inhibition is not observed in the organ culture. Thus we can be sure that it develops outside the ovary.
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4.
The synthesis of the zona pellucida continues in-vitro.
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Mit Unterstützung durch die Deutsche Forschungsgemeinschaft im Rahmen des Sonderforschungsbereiches „ Embryonal-Pharmakologie“.
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Merker, H.J., Zimmermann, B. Electron microscopic studies on the oocyte maturation in cultures of juvenile rat ovaries. Z. Zellforsch. 111, 364–378 (1970). https://doi.org/10.1007/BF00342488
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DOI: https://doi.org/10.1007/BF00342488