scholarly journals A Quantitative Description of Protoplasmic Movement During Cleavage in the Sea-Urchin Egg

1958 ◽  
Vol 35 (2) ◽  
pp. 407-424
Author(s):  
Y. HIRAMOTO
Keyword(s):  
Cell Division ◽  
Sea Urchin ◽  
Quantitative Description ◽  
Motive Force ◽  
Mitotic Apparatus ◽  
Band Theory ◽  
Cytoplasmic Granules ◽  
Carbon Particles ◽  
Sea Urchin Egg ◽  
Protoplasmic Movement

1. Protoplasmic movements during cleavage in the eggs of the heart-urchin Clypeaster japonicus have been followed by tracing the movements of cytoplasmic granules and of carbon particles adhering to the surface. 2. These movements are quantitatively described in normal eggs and in eggs whose mitotic apparatus has been destroyed by colchicine. 3. The results obtained are qualitatively similar to those obtained by Spek and by Dan and his collaborators. 4. Endoplasmic movement and changes in the length and shape of the astral rays are readily explained by the contracting-ring (band) theory. 5. The location of the motive force of cell division is discussed.

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.

Isolation of a sea urchin egg kinesin-related protein using peptide antibodies

1992 ◽  
Vol 101 (2) ◽  
pp. 291-301 ◽  
Author(s):  
D.G. Cole ◽  
W.Z. Cande ◽  
R.J. Baskin ◽  
D.A. Skoufias ◽  
C.J. Hogan ◽  
...  
Keyword(s):  
Cell Division ◽  
Molecular Mass ◽  
Sea Urchin ◽  
Heavy Chain ◽  
Relative Molecular Mass ◽  
Related Protein ◽  
Sea Urchin Egg ◽  
Conventional Kinesin ◽  
Kinesin Superfamily ◽  
Peptide Antibodies

To understand the roles of kinesin and its relatives in cell division, it is necessary to identify and characterize multiple members of the kinesin superfamily from mitotic cells. To this end we have raised antisera to peptides corresponding to highly conserved regions of the motor domains of several known members of the kinesin superfamily. These peptide antibodies react specifically with the motor domains of kinesin and ncd protein, as expected, and they also react with several polypeptides (including kinesin heavy chain) that cosediment with microtubules (MTs) precipitated from AMPPNP-treated sea urchin egg cytosol. Subsequent fractionation of ATP eluates of these MTs yields a protein of relative molecular mass 330 × 10(3) that behaves as a complex of three polypeptides that are distinct from conventional kinesin subunits or fragments thereof. This complex contains 85 kDa and 95 kDa polypeptides, which react with our peptide antibodies, and a 115 kDa polypeptide, which does not. This triplet of polypeptides, which we refer to as KRP(85/95), binds to purified sea urchin egg tubulin in an AMPPNP-enhanced, ATP-sensitive manner and induces the formation of microtubule bundles. We therefore propose that the triplet corresponds to a novel sea urchin egg kinesin-related protein.

scholarly journals Roles of kinesin and kinesin-like proteins in sea urchin embryonic cell division: evaluation using antibody microinjection.

1993 ◽  
Vol 123 (3) ◽  
pp. 681-689 ◽  
Author(s):  
B D Wright ◽  
M Terasaki ◽  
J M Scholey
Keyword(s):  
Cell Division ◽  
Sea Urchin ◽  
Heavy Chain ◽  
Mammalian Cells ◽  
Embryonic Cell ◽  
Mitotic Apparatus ◽  
Specific Antibodies ◽  
Sea Urchin Embryos ◽  
Mitotic Figures

Previous studies suggest that kinesin heavy chain (KHC) is associated with ER-derived membranes that accumulate in the mitotic apparatus in cells of early sea urchin embryos (Wright, B. D., J. H. Henson, K. P. Wedaman, P. J. Willy, J. N. Morand, and J. M. Scholey. 1991. J. Cell Biol. 113:817-833). Here, we report that the microinjection of KHC-specific antibodies into these cells has no effect on mitosis or ER membrane organization, even though one such antibody, SUK4, blocks kinesin-driven motility in vitro and in mammalian cells. Microinjected SUK4 was localized to early mitotic figures, suggesting that it is able to access kinesin in spindles. In contrast to KHC-specific antibodies, two antibodies that react with kinesin-like proteins (KLPs), namely CHO1 and HD, disrupted mitosis and prevented subsequent cell division. CHO1 is thought to exert this effect by blocking the activity of a 110-kD KLP. The relevant target of HD, which was raised against the KHC motor domain, is unknown; HD may disrupt mitosis by interfering with an essential spindle KLP but not with KHC itself, as preabsorption of HD with KHC did not alter its ability to block mitosis. These data indicate that some KLPs have essential mitotic functions in early sea urchin embryos but KHC itself does not.

scholarly journals THE EFFECT OF PENICILLIN ON EGGS OF THE SEA URCHIN, ARBACIA PUNCTULATA

1945 ◽  
Vol 28 (5) ◽  
pp. 405-413 ◽  
Author(s):  
Richard J. Henry ◽  
Maryon D. Henry
Keyword(s):  
Oxygen Consumption ◽  
Cell Division ◽  
Sea Urchin ◽  
Inhibitory Action ◽  
Initial Concentration ◽  
Arbacia Punctulata ◽  
Sea Urchin Egg

1. Penicillin in the range of concentration from 250 U/ml. to approximately 2650 U/ml. inhibits the rate of cell division of the fertilized sea urchin egg from 0 to 100 per cent. 2. Penicillin in the same range of concentrations has no effect on the oxygen consumption of the unfertilized or the fertilized eggs. 3. Penicillin is bound by some component of the sea urchin egg in amounts sufficiently large to lower the initial concentration, this binding apparently not being related to the inhibitory action.

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