scholarly journals Transition from mitosis to interphase in sea urchin first division: immunofluorescence studies of tubulin distribution in methacrylate sections.

1987 ◽  
Vol 35 (3) ◽  
pp. 343-349 ◽  
Author(s):  
P J Harris ◽  
B P Rubin
Keyword(s):  
Low Temperature ◽  
Methyl Methacrylate ◽  
Sea Urchin ◽  
Strongylocentrotus Purpuratus ◽  
Immunofluorescence Staining ◽  
Cleavage Cycle ◽  
Sea Urchin Eggs ◽  
Immunofluorescence Studies ◽  
Flat Embedding ◽  
Cell Thickness

Previous immunofluorescence studies of microtubule distribution in fertilized sea urchin eggs have suffered from poor resolution caused by cell thickness, unavoidable artifacts resulting from excessive flattening, or extraction by detergents of membranes and other lipid-containing structures that may be of interest in relation to the microtubules. To avoid these difficulties, we have developed a fixation and embedding protocol based on buffered paraformaldehyde fixation and butyl-methyl methacrylate embedment, which allows immunofluorescence staining of 0.5-1 micron sections. Polymerization artifacts are reduced by polymerizing the methacrylate at a relatively low temperature (40-45 degrees C) and by flat embedding for more uniform polymerization. Using this method, we have examined mitotic stages in the first cleavage cycle of the sea urchin Strongylocentrotus purpuratus. We provide evidence that the interphase microtubules that appear after first division are not derived from the mitotic asters but are new structures growing from organizing centers within the degenerating mitotic asters. During the transition from mitosis to interphase, there is a temporary overlap of old and new microtubules to form a very large composite aster at telophase before the old structure finally disappears.

Inositol-1,4,5-trisphosphate injection mimics fertilization potentials in sea urchin eggs

1986 ◽  
Vol 250 (2) ◽  
pp. C340-C344 ◽  
Author(s):  
B. E. Slack ◽  
J. E. Bell ◽  
D. J. Benos
Keyword(s):  
Membrane Potential ◽  
Partial Response ◽  
Sea Urchin ◽  
Time Course ◽  
Strongylocentrotus Purpuratus ◽  
Sea Urchin Eggs ◽  
Low Calcium ◽  
Inositol 1,4,5 Trisphosphate

The effects of inositol-1,4,5-trisphosphate (IP3) and of diacylglycerol (DAG) and its analogues on the membrane potential of eggs from the sea urchin Strongylocentrotus purpuratus were examined. Injection of IP3 into eggs resulted in a change in membrane potential that was similar in magnitude and time course to the fertilization potential elicited by sperm attachment. In low-calcium seawater, IP3 injection elicited a partial response. DAG and its analogues phorbol myristyl acetate and 1-oleoyl-2-acetylglycerol did not affect membrane potential either when applied by perfusion or when injected. The results indicate that IP3, but not DAG or its analogues, may be involved in the generation of the fertilization potential triggered by the interaction of sperm with sea urchin eggs.

The Respiratory and Glycolytic Enzymes of Sea-Urchin Eggs

1954 ◽  
Vol 31 (2) ◽  
pp. 208-217
Author(s):  
MARTYNAS YČAS
Keyword(s):  
Cytochrome C ◽  
Sea Urchin ◽  
Strongylocentrotus Purpuratus ◽  
Lactic Dehydrogenase ◽  
Glycolytic Pathway ◽  
Endogenous Respiration ◽  
Centrifugal Field ◽  
Lytechinus Pictus ◽  
Sea Urchin Eggs ◽  
Sea Urchin Egg

1. Activity corresponding to phosphoglucomutase, phosphohexoisomerase, aldolase, triosephosphate dehydrogenase, enolase and lactic dehydrogenase has been demonstrated in homogenates prepared from unfertilized sea-urchin eggs (Strongylocentrotus purpuratus and Lytechinus pictus). 2. The presence of cytochromes a and b1 has been confirmed. These cytochromes sediment in a relatively low centrifugal field. 3. No cytochrome c could be demonstrated, although cytochrome c is both reduced and oxidized by homogenates, and addition of cytochrome c increases the endogenous respiration and oxidation of succinate. 4. These results support the view that the usual glycolytic pathway operates in the sea-urchin egg and is the principal route of oxidation of carbohydrate.

Effect of Low Temperature Storage In Sea Urchin Eggs Viability

Cryobiology ◽  
2021 ◽  
Vol 103 ◽  
pp. 198
Author(s):  
Sara Campos ◽  
Estefanía Paredes ◽  
Jesús Troncoso
Keyword(s):  
Low Temperature ◽  
Sea Urchin ◽  
Sea Urchin Eggs ◽  
Low Temperature Storage ◽  
Temperature Storage

scholarly journals Intracellular pH of sea urchin eggs measured by the dimethyloxazolidinedione (DMO) method.

1981 ◽  
Vol 89 (2) ◽  
pp. 284-291 ◽  
Author(s):  
C H Johnson ◽  
D Epel
Keyword(s):  
Intracellular Ph ◽  
Sea Urchin ◽  
General Result ◽  
Strongylocentrotus Purpuratus ◽  
Lytechinus Pictus ◽  
Sea Urchin Eggs ◽  
Cell Divisions ◽  
Ph Microelectrodes

Intracellular pH (pH1) of sea urchin eggs and embryos was determined using DMO (5,5-dimethyl-2,4-oxazolidinedione). By this method, the pH1 of Lytechinus pictus eggs increased after fertilization from 6.86 to 7.27, and this higher pHi was maintained thereafter, as has been previously observed with pH microelectrodes. The same general result was obtained with the eggs of Strongylocentrotus purpuratus, in contrast to previous estimates of the pH of egg homogenates from this species, which had indicated a rise and then fall of pHi after fertilization. pHi did not significantly change during early cell divisions. Studies of treatments that alter pHi confirmed that ammonia alkalizes and acetate acidifies the cells. The regulation of pHi by embryos in the acidic seawater is impaired if sodium is absent, whereas unfertilized eggs can regulate pHi in acidic, sodium-free seawater.

scholarly journals SEPARATION OF INTACT CORTICAL GRANULES FROM HOMOGENATE OF UNFERTILIZED SEA URCHIN EGGS BY ZONAL CENTRIFUGATION

1969 ◽  
Vol 17 (11) ◽  
pp. 703-713 ◽  
Author(s):  
HERBERT SCHUEL ◽  
WALTER L. WILSON ◽  
JEAN R. WILSON ◽  
REGINA SCHUEL
Keyword(s):  
Acid Phosphatase ◽  
Sea Urchin ◽  
Toluidine Blue ◽  
Oxidase Activity ◽  
Short Distance ◽  
Strongylocentrotus Purpuratus ◽  
Cortical Granules ◽  
Parthenogenetic Activation ◽  
Sea Urchin Eggs ◽  
Peripheral Cytoplasm

Cortical granules are localized in the peripheral cytoplasm of mature, unfertilized eggs. The rupture of these granules constitutes one of the initial morphologically observable responses of the egg to fertilization or parthenogenetic activation. These organelles were separated from homogenates of unfertilized sea urchin eggs ( Strongylocentrotus purpuratus) by fractionation in the A-XII zonal centrifuge using sucrose density gradients constructed in (0.5 M) KCl. Cortical granules were abundant in electron micrographs of the most rapidly sedimenting population of particles. This population was rich in acid nitrophenylphosphatase activity, contained particles which stained metachromatically with toluidine blue and also contained yolk platelets. Acid phosphatase activity was also associated with several populations of slower sedimenting particles. Yolk platelets were widely distributed in the gradient, and were found in all fractions examined. The mitochondria and cytochrome oxidase activity were sedimented a short distance from the starting boundary.

Evidence that hatching enzyme of the sea urchin Strongylocentrotus purpuratus is a chymotrypsin-like protease

1988 ◽  
Vol 66 (11) ◽  
pp. 1200-1209 ◽  
Author(s):  
Laura L. Post ◽  
Regina Schuel ◽  
Herbert Schuel
Keyword(s):  
Ethyl Ester ◽  
Proteolytic Activity ◽  
Sea Urchin ◽  
Trypsin Inhibitor ◽  
Strongylocentrotus Purpuratus ◽  
Soybean Trypsin Inhibitor ◽  
Chloromethyl Ketone ◽  
Hatching Enzyme ◽  
Sea Urchin Eggs ◽  
Chymotrypsin Inhibitors

The sea urchin blastula secretes a hatching enzyme (HE) that dissolves the fertilization envelope. HE was collected from the supernatant seawater of cultures of hatched Strongylocentrotus purpuratus blastulae, and concentrated 20 times by ultrafiltration. The proteolytic activity of HE using casein as substrate was inhibited by the chymotrypsin inhibitors, chymostatin and N-tosyl-L-phenylalanine chloromethyl ketone. The activity was not inhibited by inhibitors (antipain, elastatinal, pepstatin, phosphoramidon, soybean trypsin inhibitor, and Nα-p-tosyl-L-lysine chloromethyl ketone) of other types of proteases. HE did not hydrolyze the synthetic trypsin substrate, α-N-benzoyl-L-arginine ethyl ester, but did hydrolyze the synthetic substrate of chymotrypsin, N-benzoyl-L-tyrosine ethyl ester (BTEE). The BTEEase activity of HE was completely inhibited by the chymotrypsin inhibitors chymostatin and 2-nitro-4-carboxyphenyl N,N-diphenylcarbamate (NCDC). Chymostatin inhibited the natural hatching of sea urchin blastulae. Application of HE to freshly fertilized sea urchin eggs, 2 h after insemination, caused premature dispersal of the hardened fertilization envelope. Chymostatin and NCDC inhibited HE-induced lysis of the fertilization envelope, while inhibitors of other types of proteases were ineffective. These data suggest that sea urchin HE is a chymotrypsin-like protease we call "chymostrypsin."

Histones in the first cleavage cycle of fertilised sea-urchin eggs

1978 ◽  
Vol 7 (5) ◽  
pp. 271-281 ◽  
Author(s):  
Margery G. Ord ◽  
Lloyd A. Stocken
Keyword(s):  
Sea Urchin ◽  
Cleavage Cycle ◽  
Sea Urchin Eggs
Sign in / Sign up

Export Citation Format

Share Document