Journal ArticleDOI
Protein incorporation by isolated amphibian oocytes. I. Preliminary studies.
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TLDR
Developing Xenopus oocytes removed from the ovary and divested of their outermost cellular layers (theca and surface epithelium) will incorporate protein continuously over a period of at least two to six days when cultured in vitro, implying that the outer surface epithelial layer is relatively impermeable to protein.Abstract:
Developing Xenopus oocytes removed from the ovary and divested of their outermost cellular layers (theca and surface epithelium) will incorporate protein continuously over a period of at least two to six days when cultured in vitro. The rate of protein incorporation depends upon:(a) the extent to which the donor has been stimulated by gonadotropin; (b) the size of the oocyte; and (c) the protein composition of the medium, since a mechanism exists to sequester selected protein. Protein uptake is negligible when oocytes are cultured either with all their cellular layers intact or with all their cellular layers removed. These results imply that the outer surface epithelium is relatively impermeable to protein and that the integrity of the investing follicular epithelium is essential for vigorous protein incorporation by the oocyte.read more
Citations
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Journal ArticleDOI
Oogenesis in Xenopus laevis (Daudin). I. Stages of oocyte development in laboratory maintained animals.
TL;DR: Six stages of oocyte development in the anuran Xenopus laevis can be divided into six stages based on the anatomy of the developing oocyte, and these stages have been correlated with physiological and biochemical data related to oogenesis.
Book ChapterDOI
Vitellogenesis and Oocyte Growth in Nonmammalian Vertebrates
TL;DR: The chicken egg acquires about 99% of its size during the 6 days before laying (Romanoff and Romanoff, 1949), when approximately 1 g protein is accumulated per day (Cutting and Roth, 1973).
Journal ArticleDOI
Protein incorporation by isolated amphibian oocytes III. Optimum incubation conditions
TL;DR: Available evidence indicates that protein incorporation by amphibian oocytes is mediated through a process of micropinocytosis, and several slightly improved reformulations of the standard incubation medium are provided.
Journal ArticleDOI
A two-step model for the localization of maternal mRNA in Xenopus oocytes: involvement of microtubules and microfilaments in the translocation and anchoring of Vg1 mRNA
TL;DR: A role for the cytoskeleton in localizing information in the oocyte is suggested and it is suggested that microtubules are involved in the translocation of the message to the vegetal hemisphere and microfilaments are important for the anchoring of themessage at the cortex.
Journal ArticleDOI
Oogenesis in Xenopus laevis (Daudin)
TL;DR: In this article, the relationship of estrogen, human chorionic gonadotropin (HCG), and food availability to endocytosis in developing oocytes was explored.
References
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Journal ArticleDOI
Measurement of the incorporation of radioactive amino acids into protein by a filter-paper disk method
Rusty J. Mans,G.David Novelli +1 more
TL;DR: A rapid and sensitive method has been described for the measurement of amino acid incorporation in cell-free systems and has been applied to both C14- and H3-labeled proteins.
Journal ArticleDOI
Relative roles of the pituitary, follicle cells, and progesterone in the induction of oocyte maturation in Rana pipiens
TL;DR: Results indicate that pituitary gonadotropin acts on the follicle cells to stimulate them to release a hormone that directlyact on the oocyte to induce maturation.
Journal ArticleDOI
Studies on amphibian yolk. 8. The estrogen-induced hepatic synthesis of a serum lipophosphoprotein and its selective uptake by the ovary and trasformation into yolk platelet proteins in Xenopus laevis.
Robin A. Wallace,Donald W. Jared +1 more
TL;DR: Serum chromatograms demonstrate that most of the variable labeling of the serum is the function of a single serum component, designated SLPP, which appears to transform into the two proteins of the crystalline yolk platelet, phosvitin and lipovitellin, and hence represents the precursor molecule for crystallineYolk.
Journal ArticleDOI
Studies on amphibian yolk. VII. Serum phosphoprotein synthesis by vitellogenic females and estrogen-treated males of Xenopus laevis.
R. A. Wallace,D. W. Jared +1 more
TL;DR: Female toads given 1000 units of human chorionic gonadotropin ovulated within 24 h and began to synthesize a phosphoprotein which appeared, but did not accumulate, in the serum.
Journal ArticleDOI
The in vitro differentiation of mononuclear phagocytes. ii. the influence of serum on granule formation, hydrolase production, and pinocytosis.
Zanvil A. Cohn,Belinda Benson +1 more
TL;DR: It is suggested that pinocytosis is a major regulator of granule formation and hydrolytic enzyme production by the mouse macrophage.
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