''Cleavage'' and cortical granule breakdown in Rana pipiens oocytes induced by direct microinjection of calcium

Journal Article · Thu Jan 01 04:00:00 EST 1976 · J. Cell Biol.; (United States)

DOI:https://doi.org/10.1083/jcb.71.2.395· OSTI ID:7100334

Hollinger, T G; Schuetz, A W

Microinjection of approx.0.3 ..mu..g of calcium into maturing oocytes of Rana pipiens after nuclear dissolution resulted in cleavage-like constrictions, cortical granule breakdown, and formation of a structure resembling a two-cell embryo. Mg/sup 2 +/, Na/sup +/, or K/sup +/ did not induce any of these reactions. Larger amounts of Ca/sup 2 +/-induced contraction over the entire surface of oocytes or eggs, but did not induce cleavage-like constrictions; smaller amounts of Ca/sup 2 +/ produced either a local cortical granule reaction or the formation of one large and one small ''blastomere.'' Furrow formation was not observed during normally induced maturation until after geminal vesicle breakdown. The location of microinjected Ca/sup 2 +/ determined the orientation of the resulting furrow. Ca/sup 2 +/-induced cortical granule breakdown occurred in full-grown nonmaturing oocytes near the site of injection. Cortical granule breakdown also occurred in maturing oocytes (after germinal vesicle breakdown but before second meiotic metaphase), but only in the blastomere containing the injected Ca/sup 2 +/. As expected, in mature oocytes (at second meiotic metaphase) cortical granule breakdown occurred over the entire oocyte surface, including both blastomeres. The results indicate that furrow formation and cleavage like constrictions may e directly influenced by Ca/sup 2 +/, and that functional contractile elements are present near all areas of the oocyte surface. Furthermore, Ca/sup 2 +/ injection initiates localized cortical granule breakdown in full-grown immature and maturing oocytes.

• Research Organization: Oak Ridge National Lab., TN
• OSTI ID: 7100334
• Journal Information: J. Cell Biol.; (United States), Journal Name: J. Cell Biol.; (United States) Vol. 71; ISSN JCLBA
• Country of Publication: United States
• Language: English

Related Subjects

550300* -- Cytology
59 BASIC BIOLOGICAL SCIENCES
ALKALINE EARTH METALS
AMPHIBIANS
ANIMALS
AQUATIC ORGANISMS
ATOMIC IONS
BIOLOGICAL EFFECTS
BIOLOGY
CALCIUM
CALCIUM IONS
CHARGED PARTICLES
CYTOLOGY
ELEMENTS
FROGS
GERM CELLS
IONS
MAGNESIUM IONS
METALS
MORPHOLOGICAL CHANGES
OOCYTES
POTASSIUM IONS
SODIUM IONS
VERTEBRATES