scholarly journals A Cytochemical Study of the Sulfhydryl Groups of Sea Urchin Eggs during the First Cleavage

1958 ◽  
Vol 4 (5) ◽  
pp. 615-620 ◽  
Author(s):  
Naoko Kawamura ◽  
Katsuma Dan
Keyword(s):  
Sea Urchin ◽  
Azo Dye ◽  
Sea Water ◽  
Color Intensity ◽  
Cell Stage ◽  
Cytochemical Study ◽  
Sea Urchin Eggs ◽  
Sh Groups ◽  
Precursor Material ◽  
Hemicentrotus Pulcherrimus

In the eggs of four species of echinoderms, Mespilia globulus, Pseudocentrotus depressus, Hemicentrotus pulcherrimus and Clypeaster japonicus, changes in the distribution of protein-bound SH groups from fertilization to the 2 cell stage have been studied cytochemically by use of a mercaptide-forming azo dye. In the eggs of these species, the color intensity in the cytoplasm increased upon fertilization. The astral centers and spindle during mitosis were stained deeply. When the aster formation was suppressed by ether, hyaline spots appeared in the egg cytoplasm instead of well formed astral centers and these spots were stained by the SH-specific dye. Upon recovery of such eggs in pure sea water, and when cleavage ensued, such spots disappeared and two new astral centers were reorganized. The SH-protein occurring in the centrosphere is considered to be the precursor material for the asters and spindle, and this material is apparently derived from the cytoplasm.

Cytasters induced within unfertilized sea-urchin eggs

1983 ◽  
Vol 61 (1) ◽  
pp. 175-189
Author(s):  
R. Kuriyama ◽  
G.G. Borisy
Keyword(s):  
Electron Microscopy ◽  
Sea Urchin ◽  
Sea Water ◽  
Light And Electron Microscopy ◽  
Sea Urchin Eggs ◽  
Microtubule Organizing Centres ◽  
Treatment Step

Conditions that induce the formation of asters in unfertilized sea-urchin eggs have been investigated. Monasters were formed by treatment of eggs with acidic or basic sea-water, or procaine- or thymol-containing sea-water. A second treatment step, incubation with D2O-containing, ethanol-containing or hypertonic sea-water induced multiple cytasters. The number and size of cytasters varied according to the concentration of agents and duration of the first and second treatments, and also upon the species of eggs and the season in which the eggs were obtained. Generally, a longer second treatment or a higher concentration of the second medium resulted in a higher number of cytasters per egg. Asters were isolated and then examined by light and electron microscopy. Isolated monasters apparently lacked centrioles, whereas cytasters obtained from eggs undergoing the two-step treatment contained one or more centrioles. Up to eight centrioles were seen in a single aster; the centrioles appeared to have been produced during the second incubation. Centrospheres prepared from isolated asters retained the capacity to nucleate the formation of microtubules in vitro as assayed by light and electron microscopy. Many microtubules radiated from the centre of isolated asters, whether they contained centrioles or not. This observation is consistent with many other reports that microtubule-organizing centres need not contain centrioles.

scholarly journals CHANGES IN THE POTASSIUM CONTENT OF SEA URCHIN EGGS ON FERTILIZATION

1951 ◽  
Vol 34 (3) ◽  
pp. 285-293 ◽  
Author(s):  
Anna Monroy Oddo ◽  
Maria Esposito
Keyword(s):  
Sea Urchin ◽  
Sea Water ◽  
Paracentrotus Lividus ◽  
Potassium Content ◽  
Minimum Point ◽  
Sea Urchin Eggs ◽  
Maximum Loss ◽  
Arbacia Lixula

In the eggs of Arbacia lixula and Paracentrotus lividus an uptake of K occurs during the first 10 minutes following fertilization. Between 10 and 40 minutes K is then released. Both in Arbacia and in Paracentrotus the minimum point of the curve coincides with the nuclear streak stage. A maximum loss of 25 per cent in Arbacia and 20 per cent in Paracentrotus with respect to the amount present in the unfertilized eggs has been found. From 40 minutes up to 1 hour K undergoes a further increase and when the first cleavage sets in the same amount of K is present as in the unfertilized eggs. By treating the eggs with K-free artificial sea water it has been established that about 60 per cent of the K content of the eggs is in a non-diffusible condition. Also under such conditions the eggs when fertilized are able to take up even the very small amount of K present in the medium that was released by them prior to fertilization.

Some Experiments on Sea-urchin Eggs with Desoxynucleic Acids from Sea-urchin Sperms

Development ◽  
1953 ◽  
Vol 1 (3) ◽  
pp. 261-262
Author(s):  
Sven Hörstadius
Keyword(s):  
New York ◽  
Sea Urchin ◽  
Sea Water ◽  
Water Injection ◽  
Dark Field ◽  
The Other ◽  
Columbia University ◽  
Sea Urchin Eggs ◽  
King's College ◽  
Fertilization Membrane

Dr. I. Joan Lorch, of King's College, London, and I have made some experiments on sea-urchin eggs with desoxynucleic acids (DNA) prepared from sperms of several sea-urchin species by Professor Erwin Chargaff, of Columbia University, New York. Unfertilized eggs did not react when put into a solution of DNA in sea-water. Injection of a small amount of DNA dissolved in Callan's solution had the following consequences. If the DNA did not mix with the cytoplasm but remained as a distinct droplet, the egg could be fertilized. The droplet moved slowly towards the surface and ran out of the egg. This sometimes only occurred after several cleavages. Such eggs developed normally. If, on the other hand, the DNA mixed with the cytoplasm the egg became activated. A fertilization membrane was raised. The surface layer in dark field changed in colour from yellow to white as is the case upon fertilization.

Displacement of Valine From Intact Sea-Urchin Eggs by Exogenous Amino Acids

1968 ◽  
Vol 3 (4) ◽  
pp. 515-527
Author(s):  
J. PIATIGORSKY ◽  
A. TYLER
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Sea Urchin ◽  
Sea Water ◽  
The Other ◽  
Metabolic Product ◽  
Primary Factor ◽  
Lytechinus Pictus ◽  
Sea Urchin Eggs ◽  
Neutral Amino Acids

Unfertilized and fertilized eggs of the sea urchin Lytechinus pictus were preloaded with [14C]valine and exposed to individual solutions of each of the twenty ‘coded’ [12C]amino acids in artificial sea water. After 1 h incubation the amount of radioactivity in the medium was determined. The radioactivity was effectively displaced by most of the other neutral [12C]amino acids that are known to compete with valine for uptake. A chromatographic test with fertilized eggs showed the displaced radioactivity to be [14C]valine and not some metabolic product. Addition of acidic, basic or some neutral amino acids that are known to be poor inhibitors of valine uptake did not cause significant quantities of label to appear in the medium. For the unfertilized eggs, the concentration of acid-soluble label remained many hundreds of times greater in the egg fluid than in the sea water. Tests indicated that efflux of [14C]valine and subsequent competition for re-entry is a primary factor responsible for the displacement phenomenon. That this may not be the sole factor is suggested by the fact that some amino acids that are known to be powerful inhibitors of valine uptake were found to be only weak displacers of [14C]valine. Neither [14C]arginine nor [14C]glutamic acid were displaced in significant amounts from preloaded unfertilized or fertilized eggs by any of the tested [12C]amino acids. Attempts were made to utilize the displacement of [12C]valine to elevate the incorporation of [14C]valine and of other labelled amino acids into protein by intact eggs. Unfertilized and fertilized eggs were pretreated with related [12C]amino acids and then exposed to [14C]valine or a mixture of [14C]amino acids. The results varied in the different tests, ranging from no significant increase to 2-fold.

Cortical Granule Exocytosis and Fertilization Coat Elevation is Reduced in Aging Sea Urchin Eggs

2000 ◽  
Vol 6 (S2) ◽  
pp. 966-967
Author(s):  
Amitabha Chakrabarti ◽  
Heide Schatten
Keyword(s):  
Plasma Membrane ◽  
Sea Urchin ◽  
Sea Water ◽  
Secretory Granules ◽  
Cortical Granule ◽  
Cortical Granules ◽  
Lytechinus Pictus ◽  
Sea Urchin Eggs ◽  
Cortical Granule Exocytosis ◽  
Granule Secretion

Cortical granules are specialized Golgi-derived membrane-bound secretory granules that are located beneath the plasma membrane in unfertilized sea urchin eggs. Upon fertilization cortical granules discharge in a reaction induced by calcium and release their contents between the plasma membrane and a thin vitelline layer that lines the plasma membrane. Microvilli at the plasma membrane elongate incorporting cortical granule membranes during elongation. The vitelline layer elevates and becomes the egg's fertilization coat that hardens and serves as physical block to polyspermy. While we do not understand the precise mechanisms that participate in cortical granule discharge it is believed that actin plays a role in this process. Because actin and calcium metabolism is affected in aging cells we investigated if cortical granule secretion is affected in aging sea urchin eggs.Lytechinus pictus eggs were obtained by intracoelomic injection of 0.5M KCI to release the eggs into sea water at 23°C.

Fertilization envelope assembly in sea urchin eggs inseminated in chloride-deficient sea water: II. Biochemical effects

1990 ◽  
Vol 25 (2) ◽  
pp. 177-185 ◽  
Author(s):  
Jeffrey D. Green ◽  
Patricia S. Glas ◽  
Sou-De Cheng ◽  
John W. Lynn
Keyword(s):  
Sea Urchin ◽  
Sea Water ◽  
Sea Urchin Eggs ◽  
Biochemical Effects

Non-plasmalemmal localisation of the major ganglioside in sea urchin eggs

Zygote ◽  
1993 ◽  
Vol 1 (3) ◽  
pp. 215-223 ◽  
Author(s):  
Hidehiko Shogomori ◽  
Kazuyoshi Chiba ◽  
Hideo Kubo ◽  
Motonori Hoshi
Keyword(s):  
Endoplasmic Reticulum ◽  
Sea Urchin ◽  
Indirect Immunofluorescence ◽  
Immunofluorescence Microscopy ◽  
Mitotic Apparatus ◽  
Sea Urchin Eggs ◽  
Indirect Immunofluorescence Microscopy ◽  
The One ◽  
Major Ganglioside ◽  
Hemicentrotus Pulcherrimus

SummaryM5 ganglioside (NeuGcα2–6Glcβl-' Cer) is the predominant glycosphingolipid in sea urchin eggs. Distribution of M5 ganglioside was studied in unfertilised and fertilised eggs of the sea urchin Hemicentrotus pulcherrimus by indirect immunofluorescence microscopy. In the cortices of unfertilised eggs, anti-M5 antibody strongly stained the submembranous, polygonal and tubular network of endoplasmic reticulum that was revealed by a membrane-staining dye, DiIC18(3). In addition to the cortical network of endoplasmic reticulum, at least two morphologically distinct vesicles were positive to the antibody. In the cortices isolated from fertilised eggs 30 min after insemination, the antibody stained only a similar network of endoplasmic reticulum, presumably the one reconstructed 5–10 min after fertilisation. During mitosis the endoplasmic reticulum is known to aggregate within the asters of the mitotic apparatus. Indeed, the antibody stained the asters and (more strongly) the vesicular components attaching to the periphery of the mitotic apparatus.

scholarly journals Activation of sea urchin eggs by inositol phosphates is independent of external calcium

1988 ◽  
Vol 252 (1) ◽  
pp. 257-262 ◽  
Author(s):  
I Crossley ◽  
K Swann ◽  
E Chambers ◽  
M Whitaker
Keyword(s):  
Sea Urchin ◽  
Calcium Ions ◽  
Sea Water ◽  
Inositol Phosphates ◽  
Inositol Phosphate ◽  
Egg Activation ◽  
Lytechinus Variegatus ◽  
Lytechinus Pictus ◽  
Sea Urchin Eggs ◽  
External Calcium

We investigated the contribution of external calcium ions to inositol phosphate-induced exocytosis in sea urchin eggs. We show that: (a) inositol phosphates activate eggs of the sea urchin species Lytechinus pictus and Lytechinus variegatus independently of external calcium ions; (b) the magnitude and duration of the inositol phosphate induced calcium changes are independent of external calcium; (c) in calcium-free seawater, increasing the volume of inositol trisphosphate solution injected decreased the extent of egg activation; (d) eggs in calcium-free sea water are more easily damaged by microinjection; microinjection of larger volumes increased leakage from eggs pre-loaded with fluorescent dye. We conclude that inositol phosphates do not require external calcium ions to activate sea urchin eggs. This is entirely consistent with their role as internal messengers at fertilization. The increased damage caused to eggs in calcium-free seawater injected with large volumes may allow the EGTA present in the seawater to enter the egg and chelate any calcium released by the inositol phosphates. This may explain the discrepancy between this and earlier reports.

scholarly journals STUDIES ON SULFHYDRYL GROUPS DURING CELL DIVISION OF SEA URCHIN EGG

1960 ◽  
Vol 8 (3) ◽  
pp. 603-607 ◽  
Author(s):  
Hikoichi Sakai
Keyword(s):  
Cell Division ◽  
Sea Urchin ◽  
Sulfhydryl Groups ◽  
Cell Stage ◽  
Sea Urchin Eggs ◽  
Maximum Value ◽  
Sea Urchin Egg ◽  
Egg Cortex

Masses of cortices of both unfertilized and fertilized sea urchin eggs can be isolated by crushing eggs in hypotonic MaCl2 (0.1 M) solution. The amount of cortical material in terms of protein-N increases steadily after fertilization until the monaster stage and thereafter remains almost constant until well into the two-cell stage. The amount of bound—SH per protein-N of the egg cortex also increases after fertilization, reaches a maximum value at the amphiaster stage and thereafter decreases rapidly as the cleavage of the cell proceeds.

Sign in / Sign up

Export Citation Format

Share Document