ULTRASTRUCTURE OF CORTICAL GRANULES IN SEA URCHIN EGGS STAINED WITH PHOSPHOTUNGSTIC ACID
نویسندگان
چکیده
منابع مشابه
Isolation and characterization of plasma membrane-associated cortical granules from sea urchin eggs
Cortical granules, which are specialized secretory organelles found in ova of many organisms, have been isolated from the eggs of the sea urchins Arbacia punctulata and Strongylocentrtus pupuratus by a simple, rapid procedure. Electron micropscope examination of cortical granules prepared by this procedure reveals that they are tightly attached to large segments of the plasma membrane and its a...
متن کاملIsolation and characterization of sea urchin egg cortical granules
A method has been developed to isolate cortical granules (CG) free in suspension. It involves the mechanical disruption of the CG from CG lawns (CGL; Dev. Biol. 43:62-74, 1975) and concentration of the CG by low speed centrifugation. The isolated CG are intact and are a relatively pure population as judged by electron microscopy. Granule integrity is confirmed by the fact that isolated intact C...
متن کاملIsolation of cortical material from sea urchin eggs by centrifugation.
Although the surface layers of the sea urchin egg are the site of dramatic changes at fertilization, little is actually known about the submicroscopic structure of the surface layers, their chemistry, or the real nature of the physiological changes that are collectively referred to as the cort ical reac tiom. Excluding the jelly, the surface layers of the unfertilized egg that have been recogni...
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 کاملCleavage of Sea-urchin Eggs in Colchicine
INTRODUCTION We have recently put forward a theory linking mitosis with cleavage, in which we suggest that cleavage is caused by an expansion of the cell cortex which starts at either pole of the cell and later moves round to the region of the furrow (Mitchison, 1952). There is evidence that this expansion is brought about by substances diffusing from the two groups of daughter chromosomes whic...
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ژورنال
عنوان ژورنال: ACTA HISTOCHEMICA ET CYTOCHEMICA
سال: 1969
ISSN: 0044-5991,1347-5800
DOI: 10.1267/ahc.2.68