The Rate of Elongation and Constriction of Dividing Sea-Urchin Eggs as a Test of a Mathematical Theory of Cell Division

1943 ◽  
Vol 16 (2) ◽  
pp. 162-171 ◽  
Author(s):  
Ralph Buchsbaum ◽  
Robert R. Williamson
Keyword(s):  
Cell Division ◽  
Sea Urchin ◽  
Mathematical Theory ◽  
Sea Urchin Eggs

scholarly journals Behavior of centrosomes during fertilization and cell division in mouse oocytes and in sea urchin eggs.

1986 ◽  
Vol 83 (1) ◽  
pp. 105-109 ◽  
Author(s):  
H. Schatten ◽  
G. Schatten ◽  
D. Mazia ◽  
R. Balczon ◽  
C. Simerly
Keyword(s):  
Cell Division ◽  
Sea Urchin ◽  
Sea Urchin Eggs ◽  
Mouse Oocytes

scholarly journals Effects of caffeine and other methylxanthines on the development and metabolism of sea urchin eggs. Involvement of NADP and glutathione.

1976 ◽  
Vol 68 (3) ◽  
pp. 440-450 ◽  
Author(s):  
J Nath ◽  
J I Rebhun
Keyword(s):  
Cell Division ◽  
Sea Urchin ◽  
Reductase Activity ◽  
Inhibitory Effect ◽  
Pentose Phosphate ◽  
Nad Kinase ◽  
Mitotic Apparatus ◽  
Sea Urchin Eggs ◽  
Glutathione Reductase Activity

Methylxanthines (MX) inhibit cell division in sea urchin and clam eggs. This inhibitory effect is not mediated via cAMP. MX also inhibit respiration in marine eggs, at concentrations which inhibit cleavage. Studies showed that no changes occurred in ATP and ADP levels in the presence of inhibitory concentrations of MX, indicating an extra-mitochondrial site of action for the drug. Subsequent studies revealed decreased levels of NADP+ and NADPH, when eggs were incubated with inhibitory concentrations of MX, but no change in levels of NAD+ and NADH. MX did not affect the pentose phosphate shunt pathway and did not have any effect on the enzyme NAD+ -kinase. Further studies showed a marked inhibitory effect on the glutathione reductase activity of MX-treated eggs. Reduced glutathione (GSH) could reverse the cleavage inhibitory effect of MX. Moreover, diamide, a thiol-oxidizing agent specific for GSH in living cells, caused inhibition of cell division in sea urchin eggs. Diamide added to eggs containing mitotic apparatus (MA) could prevent cleavage by causing a dissolution of the formed MA. Both MX and diamide inhibit a Ca2+-activated ATPase in whole eggs. The enzyme can be reactivated by sulfhydryl reducing agents added in the assay mixture. In addition, diamide causes an inhibition of microtubule polymerization, reversible with dithioerythritol. All experimental evidence so far suggests that inhibition of mitosis in sea urchin eggs by MX is mediated by perturbations of the in vivo thiol-disulfide status of target systems, with a primary effect on glutathione levels.

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.

On the role of serotonin and 5-methoxy-tryptamine in the regulation of cell division in sea urchin eggs

1983 ◽  
Vol 98 (1) ◽  
pp. 37-46 ◽  
Author(s):  
F. Renaud ◽  
E. Parisi ◽  
A. Capasso ◽  
P. De Prisco
Keyword(s):  
Cell Division ◽  
Sea Urchin ◽  
Sea Urchin Eggs

scholarly journals FURTHER STUDIES ON CELL DIVISION WITHOUT MITOTIC APPARATUS IN SEA URCHIN EGGS

1965 ◽  
Vol 25 (1) ◽  
pp. 161-167 ◽  
Author(s):  
Y. Hiramoto
Keyword(s):  
Cell Division ◽  
Sea Urchin ◽  
Sea Water ◽  
Sucrose Solution ◽  
Mitotic Apparatus ◽  
Sea Urchin Eggs ◽  
Paraffin Oil

A large quantity of paraffin oil, sucrose solution, or sea water was injected into the eggs of the heart urchin Clypeaster japonicus shortly before the onset of the first cleavage. The injected oil became spherical, pushing the mitotic apparatus aside. The sucrose solution mixed with the protoplasm and caused disintegration of the mitotic apparatus, and the sea water formed a vacuole at the center of the cell. In all these cases, cleavage may take place almost normally in spite of the absence of the mitotic apparatus or its displacement within the cell. In some eggs, furrowing may take place when more than fifty per cent of the endoplasm has been replaced with sea water before onset of cleavage.

scholarly journals THE RELATION BETWEEN THE ELECTRICAL CONDUCTIVITY OF THE EXTERNAL MEDIUM AND THE RATE OF CELL DIVISION IN SEA URCHIN EGGS

1923 ◽  
Vol 5 (6) ◽  
pp. 807-814 ◽  
Author(s):  
R. S. Lillie ◽  
Ware Cattell
Keyword(s):  
Electrical Conductivity ◽  
Cell Division ◽  
Sea Urchin ◽  
Sea Water ◽  
External Medium ◽  
Sugar Solution ◽  
Cleavage Rate ◽  
Sea Urchin Eggs

Dilution of sea water with isotonic sugar solution leaves the rate of cleavage of Arbacia eggs almost unchanged until the proportion of sea water is decreased to 20 or 25 volumes per cent. From this point cleavage becomes progressively slower with further dilution. Many eggs fail to cleave at dilutions of 5 to 6 volumes per cent. No cleavage occurs in 2 volumes per cent sea water or in pure sugar solution. Eggs returned from these media to sea water resume cleavage and development. There is thus no relation between the rate of cleavage and the electrical conductivity of the medium, except possibly within the range of dilutions from 20 to 5 volumes per cent sea water. In this range cleavage rate decreases as conductivity decreases, but the relation is not a linear one.

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