Regional Response to Cytochalasin B of the Equatorial Cell Cortex in Sea-Urchin Eggs during the First Mitosis. (surface architecture/cortical microfilaments/cytochalasin B/sea-urchin egg/first mitosis)
نویسندگان
چکیده
منابع مشابه
Nuclear-cytoplasmic Relations in the Mitosis of Sea Urchin Eggs
Sea urchin eggs were cut into halves. The nucleate and anucleate halves and whole eggs were irradiated with gamma-rays and then fertilized with normal sperm. The first mitosis of the diploid half-egg was more delayed than the division of the whole egg. There was a small, but highly significant, delay of the mitosis of the haploid half-egg, thus demonstrating cytoplasmic sensitivity to ionizing ...
متن کاملElectron Microscope Study of Mitosis in Sea Urchin Blastomeres
The fine structure of cells at different stages of the mitotic cycle was studied in the blastomeres of 6-hour-old embryos of the sea urchin Strongylocentrotus purpuratus. The material was fixed in 1 per cent osmium tetroxide in sea water, buffered with veronal-acetate to pH 7.5, embedded in Araldite, and sectioned with glass knives. The aster, as it forms around the centriole, has the appearanc...
متن کاملPolyphosphoinositide metabolism during the fertilization wave in sea urchin eggs.
A transient increase in intracellular free calcium is believed to be the signal responsible for the stimulation of the egg metabolism at fertilization and the resumption of the cell cycle. We have studied how the polyphosphoinositides (PPI) turn over at fertilization in sea urchin eggs, in order to determine the relationship between the metabolism of these lipids and the calcium signal. We comp...
متن کاملActive cyclin B-cdc2 kinase does not inhibit DNA replication and cannot drive prematurely fertilized sea urchin eggs into mitosis.
Feedback mechanisms preventing M phase occurrence before S phase completion are assumed to depend on inhibition of cyclin B-cdc2 kinase activation by unreplicated DNA. In sea urchin, fertilization stimulates protein synthesis and releases eggs from G1 arrest. We found that in the one-cell sea urchin embryo cyclin B-cdc2 kinase undergoes partial activation before S phase, reaching in S phase a l...
متن کاملAction of Colcemid in Sea Urchin Eggs
The effects of Colcemid, the deacetyl-N-methyl derivative of colchicine, on the eggs of Arbacia punctulata were investigated. Colcemid in concentrations of 2.7 x 10(-5)M or greater blocks syngamy (the fusion of the pronuclei) in these eggs. Although a tenfold decrease in concentration of Colcemid usually permits the pronuclei to fuse, the subsequent division is blocked. In the sea urchin egg, t...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Development, Growth and Differentiation
سال: 1989
ISSN: 0012-1592,1440-169X
DOI: 10.1111/j.1440-169x.1989.00257.x