Centrifugal bisection of starfish oocytes
نویسندگان
چکیده
منابع مشابه
Centrosome destined to decay in starfish oocytes.
In contrast to the somatic cell cycle, duplication of the centrioles does not occur in the second meiotic cycle. Previous studies have revealed that in starfish each of the two centrosomes in fully-grown immature oocytes consists of two centrioles with different destinies: one survives and retains its reproductive capacity, and the other is lost after completion of meiosis. In this study, we in...
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The high degree of ultrastructural organization of microtubular crystals (1, 2) produced in mammalian cells by incubation with Vinca alkaloids, suggested that these crystals would be birefringent in polarized light. We now report the induction by vinblastine sulfate (VBL) of birefringent crystals in unfertilized oocytes of the starfish Pisaster ochraceous . Mature ovaries were removed, placed i...
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In invertebrates oocytes or eggs, the fertilization or activation potential establishes the fast electrical block to polyspermy and, in some species, provides the Ca2+ influx which contributes to the following intracellular Ca2+ wave. In echinoderms, the molecule triggering the activation potential is still unknown. The aim of this study was to assess whether nicotinic acid-adenine dinucleotide...
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We found that in starfish oocytes two different enzymes, phosphatidylserine synthase-1 (PSS1) and -2 (PSS2), which synthesize phosphatidylserine by a base-exchange reaction, are present. We studied phosphatidylserine synthesis in immature oocytes which still contain the nucleus (germinal vesicles) and in mature cells, in which the re-initiation of the meiotic cycle induced by the hormone 1-meth...
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Intracellular pH was recorded in immature starfish oocytes using pH-sensitive microelectrodes, and inwardly rectifying potassium currents were measured under voltage clamp. When the intracellular pH was lowered using acetate-buffered artificial sea water from the normal value of 7.09 to 5.9, inward rectification was completely blocked. The relationship between inward rectification and internal ...
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ژورنال
عنوان ژورنال: Development, Growth and Differentiation
سال: 1996
ISSN: 0012-1592,1440-169X
DOI: 10.1046/j.1440-169x.1996.t01-1-00007.x