scholarly journals IMMUNO-ELECTRON MICROSCOPE ANALYSIS OF THE SURFACE LAYERS OF THE UNFERTILISED SEA URCHIN EGG

1964 ◽  
Vol 23 (3) ◽  
pp. 629-650 ◽  
Author(s):  
Jane Baxandall ◽  
P. Perlmann ◽  
B. A. Afzelius
Keyword(s):  
Structural Changes ◽  
Paracentrotus Lividus ◽  
Vitelline Membrane ◽  
Antigenic Determinants ◽  
Cortical Granules ◽  
Surface Layers ◽  
Antibody Treatment ◽  
Heat Stable ◽  
Antigenic Sites ◽  
Sea Urchin Egg

The immunological properties of the surface layers of Paracentrotus lividus eggs have been studied further by using ferritin-labelled antibody to localise specific antigenic sites. In order to detect a wider spectrum of antigenic determinants, several antisera against egg and jelly substance have been employed in combination with absorption procedures using lyophilised antigen. This use of absorbed antisera was made feasible by adding ferritin label in a second antiserum layer of ferritin-anti-γ-globulin. Eggs were treated with antibody for short periods to detect antigenic sites without incurring structural changes (shown in previous paper) resulting from long antibody treatment. Unspecific ferritin uptake, found in pinocytotic vesicles and yolk granules, is considered in relation to yolk formation. The jelly layer, found to be immunologically heterogeneous, included one component interacting with antijelly γ-globulin and one with antiegg γ-globulin. The vitelline membrane proved to be rich in egg antigens (heat-stable and heat-labile). The role of this layer in specificity of fertilisation, parthenogenetic activation, and the possibility of being analogous to a basement membrane are discussed. Few antigenic sites were found on the plasma membrane with antiegg γ-globulin. This γ-globulin resulted in some specific labelling of cortical granules and its action is considered in relation to the permeability properties of the egg.

scholarly journals IMMUNO-ELECTRON MICROSCOPE ANALYSIS OF THE SURFACE LAYERS OF THE UNFERTILISED SEA URCHIN EGG

1964 ◽  
Vol 23 (3) ◽  
pp. 609-628 ◽  
Author(s):  
Jane Baxandall ◽  
P. Perlmann ◽  
B. A. Afzelius
Keyword(s):  
Paracentrotus Lividus ◽  
Ultrastructural Level ◽  
Cortical Granules ◽  
Parthenogenetic Activation ◽  
Jelly Coat ◽  
Heat Stable ◽  
Sea Urchin Egg ◽  
Γ Globulins ◽  
Electron Microscope Analysis ◽  
Species Specific

The response of unfertilised Paracentrotus lividus eggs to γ-globulin fractions of antisera against isolated homologous jelly coat substance or homologous homogenates of jellyless eggs has been studied at the ultrastructural level. The antijelly γ-globulin caused precipitation of the jelly layer, the density of precipitation varying between different eggs and being proportional to the γ-globulin concentration. Agglutination of the jelly substance of adjacent eggs, which is species specific, occurred frequently with higher γ-globulin concentrations. Antiegg γ-globulins (from antiserum against total homogenates of jelly-free eggs or the heat-stable fraction thereof) did not produce these effects. Instead, these γ-globulins caused various structural alterations mostly representing stages in parthenogenetic activation. This species-specific activation was induced by the reaction of antibodies with some heat-stable egg antigens different from those involved in jelly precipitation. Surface alterations included the formation of small papillae, membrane blisters, hyaline layer, and activation membrane, the release of material from the cell surface, and the breakdown of cortical granules. These alterations were dependent on both γ-globulin concentration and the variable reactivity among different females. Aster formation, found intracellularly, verified that the surface responses represented real parthenogenetic activation and were not the result of immune lysis. No such alterations appeared in the controls.

The Thickness of the Cortex of the Sea-Urchin Egg and the Problem of the Vitelline Membrane

1956 ◽  
Vol s3-97 (37) ◽  
pp. 109-121
Author(s):  
J. M. MITCHISON
Keyword(s):  
Sea Urchin ◽  
Granular Layer ◽  
Paracentrotus Lividus ◽  
Vitelline Membrane ◽  
Cortical Granules ◽  
A Value ◽  
Sea Urchin Egg ◽  
Hyaline Zone ◽  
Sperm Aster ◽  
Arbacia Lixula

The gelated cortex of a sea-urchin egg can be seen as a granular layer at the edge of the hyaline zone in a centrifuged egg. Measurements were made of the thickness of this layer in the eggs of Paracentrotus lividus and Arbacia lixula at various stages of development from the unfertilized egg to the first cleavage. The thickness was roughly 2 µ in living eggs, and 1.15-1.35 µ in sections of fixed eggs. There were no appreciable changes in the thickness up to the first cleavage, and it is concluded that a value of 1.5 µ can be taken as an approximate figure for all stages. The cortex is usually invisible in normal eggs either living or in section, but in the case of sections of fertilized Arbacia eggs it can be seen as a vacuolated layer. The thickness of this layer was found to be 1.13 µ at the sperm aster stage and 1.50 µ at cleavage. In these eggs at cleavage, there were no signs either of differences in thickness at different regions of the surface or of a differentiated region of the cytoplasm ahead of the furrow. There were no clear indications of the presence of a vitelline membrane either in living or fixed eggs. A layer about 0.8 µ thick, pale with iron haematoxylin, was found at the edge of sections of unfertilized eggs which had been fixed in Bouin, but not with those which had been fixed in Flemming. This is probably the outer layer of the cortex which normally contains the cortical granules.

scholarly journals The Block to Polyspermy in Sturgeon and Trout with Special Reference to the Role of Cortical Granules (Alveoli)

Development ◽  
1961 ◽  
Vol 9 (1) ◽  
pp. 173-190
Author(s):  
A. S. Ginsburg
Keyword(s):  
Sea Urchins ◽  
Morphological Changes ◽  
Cortical Layer ◽  
Vitelline Membrane ◽  
Cortical Granules ◽  
Sea Urchin Egg ◽  
Protective Reaction ◽  
Fertilization Membrane ◽  
The Subject

When a monospermic egg is fertilized, the attachment of the fertilizing spermatozoon to the egg surface provokes a protective reaction that prevents all ut one spermatozoon from entering the egg; this is the block to polyspermy. The nature of the defence mechanism against polyspermy has been the subject of many investigations, performed mainly on the eggs of sea urchins. It was established that on fertilization of the sea-urchin egg a cortical reaction takes place consisting of morphological changes in the cortical layer, spreading in wave-like fashion from the point of the spermatozoon attachment over the whole egg surface: the light scattering and the intensity of birefringence undergo changes; extrusion of mucopolysaccharide granules takes place, accompanied by the separation of the vitelline membrane and its transformation into the fertilization membrane; the perivitelline space appears and the hyaline layer is then formed at the egg surface (see Runnström, 1952; Rothschild, 1956; Allen, 1958).

Common Antigenic Sites in Human, Bovine and Porcine Fibrinogens

1981 ◽  
Vol 45 (02) ◽  
pp. 169-172 ◽  
Author(s):  
Czeslaw S Cierniewski
Keyword(s):  
Antigenic Determinants ◽  
Antigenic Sites ◽  
Specific Antisera ◽  
Antigenic Homology ◽  
Polypeptide Chains ◽  
Fibrinogen Molecule

SummarySpecific antisera to the Aα, Bβ and γ chains of porcine fibrinogen were used to characterize an antigenic homology of human, bovine, and porcine fibrinogens. Antigenic determinants shared by these fibrinogens were mostly formed by the Aα chain. However, in the case of bovine and porcine fibrinogens they were also found in the Bβ and γ polypeptide chains. The results reported here show that the Aα chain determinants exposed on the intact fibrinogen molecule are conserved to a considerably larger extent than those of the Bβ and γ chains.

scholarly journals Poisson-distributed active fusion complexes underlie the control of the rate and extent of exocytosis by calcium.

1996 ◽  
Vol 134 (2) ◽  
pp. 329-338 ◽  
Author(s):  
S S Vogel ◽  
P S Blank ◽  
J Zimmerberg
Keyword(s):  
Poisson Process ◽  
Sea Urchin ◽  
Physiological Responses ◽  
Cortical Granule ◽  
Cortical Granules ◽  
Granule Exocytosis ◽  
Calcium Dependence ◽  
Sea Urchin Egg ◽  
High Calcium ◽  
Cortical Granule Exocytosis

We have investigated the consequences of having multiple fusion complexes on exocytotic granules, and have identified a new principle for interpreting the calcium dependence of calcium-triggered exocytosis. Strikingly different physiological responses to calcium are expected when active fusion complexes are distributed between granules in a deterministic or probabilistic manner. We have modeled these differences, and compared them with the calcium dependence of sea urchin egg cortical granule exocytosis. From the calcium dependence of cortical granule exocytosis, and from the exposure time and concentration dependence of N-ethylmaleimide inhibition, we determined that cortical granules do have spare active fusion complexes that are randomly distributed as a Poisson process among the population of granules. At high calcium concentrations, docking sites have on average nine active fusion complexes.

Structural changes in the surface layers of sealing material S-137 in high-speed dry friction

1974 ◽  
Vol 7 (6) ◽  
pp. 660-663
Author(s):  
N. L. Golego ◽  
M. E. Belitskii ◽  
A. D. Gaidarenko ◽  
V. A. Lyashko
Keyword(s):  
Dry Friction ◽  
High Speed ◽  
Structural Changes ◽  
Surface Layers ◽  
Sealing Material

Conformational Alterations of α2-Antiplasmin Induced by Complex Formation with Plasmin

1979 ◽  
Author(s):  
E.F. Plow ◽  
B. Wiman ◽  
D. Collen
Keyword(s):  
Complex Formation ◽  
Structural Changes ◽  
Limited Proteolysis ◽  
Terminal Region ◽  
The Other ◽  
Antigenic Determinants ◽  
Chemical Analyses ◽  
Large Fragment ◽  
Reactive Site ◽  
Immunodiffusion Analysis

The conformational and structural changes induced in the α2-antiplasmin (AP) molecule by complex formation with plasmin have been analyzed utilizing quantitative radioimmuno-chemical analyses. Complexes prepared in plasmin excess -(PAP-P) and therefore subjected to limited proteolysis and complexes prepared in AP excess (PAP-A) have been compared with free AP. With AP antiserum, PAP-A, PAP-P and AP yielded reactions of complete identity by immunodiffusion analysis. In radioimmunoassay, however, these were clearly distinguished, and four distinct sets of antigenic determinants were delineated. Set I determinants were expressed equivalently by PAP-P, PAP-A and AP and were, therefore, not altered by complex formation. This set was recognized by 90% of the antibodies, and the determinants were all included within a large fragment of Mr 60,000 derived from the NH2-terminal region of AP. The other three sets of determinants were modulated by complex formation. Set II was expressed by PAP-A and AP but not by PAP-P, and these were sensitive to proteolysis by plasmin. Set III determinants were expressed only by AP and were localized to a peptide of Mr 8,000 derived from the COOH-terminal region of AP. Set IV determinants were also present only on AP but were not present in the peptide and required an intact reactive site in AP for expression. Thus, there is evidence for multiple conformational modulations in AP induced by complex formation, and these modulations can be pinpointed to specific loci within the AP molecule.

Purification of cortical granules from unfertilized sea urchin egg homogenates by zonal centrifugation

1972 ◽  
Vol 29 (3) ◽  
pp. 307-320 ◽  
Author(s):  
H. Schuel ◽  
W.L. Wilson ◽  
R.S. Bressler ◽  
J.W. Kelly ◽  
J.R. Wilson
Keyword(s):  
Sea Urchin ◽  
Cortical Granules ◽  
Sea Urchin Egg

scholarly journals DIRECT ISOLATION OF THE HYALINE LAYER PROTEIN RELEASED FROM THE CORTICAL GRANULES OF THE SEA URCHIN EGG AT FERTILIZATION

1970 ◽  
Vol 45 (3) ◽  
pp. 615-622 ◽  
Author(s):  
R. E. Kane
Keyword(s):  
Protein Content ◽  
Sea Urchin ◽  
Insoluble Fraction ◽  
Glycerol Solution ◽  
Cortical Granules ◽  
Simple Method ◽  
Quantitative Measurements ◽  
Hawaiian Species ◽  
Sea Urchin Egg

Treatment of the eggs of the sea urchin with a 1 M solution of glycerol at fertilization allows the recovery from this solution of the protein released from the cortical granules, including that which would normally give rise to the hyaline layer. The calcium-gelable protein previously extracted from whole eggs and from isolated cortical material was found to be present in the glycerol solution, confirming its localization in the cortical granules and its role in the hyaline layer. Quantitative measurements on the eggs of two Hawaiian species, Colobocentrotus atratus and Pseudoboletia indiana, which have the widest variation in the gel protein content, demonstrated that a proportionate amount of this material was released at fertilization in these species, which correlates with the thickness of the hyaline layer in the two cases. In addition, the calcium-insoluble fraction of Sakai can be extracted from these eggs after removal of the hyaline protein by glycerol, showing that this is a different material. A simple method for the separation of the hyaline protein from the calcium-insoluble fraction in solution is provided.

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