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.

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.

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 Multispecies Identification of Oilseed- and Meat-Specific Proteins and Heat-Stable Peptide Markers in Food Products

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1577
Author(s):  
Klaudia Kotecka-Majchrzak ◽  
Natalia Kasałka-Czarna ◽  
Agata Sumara ◽  
Emilia Fornal ◽  
Magdalena Montowska
Keyword(s):  
Limit Of Detection ◽  
Raw Materials ◽  
Meat Products ◽  
Food Products ◽  
Plant Raw Materials ◽  
Heat Stable ◽  
2S Albumins ◽  
Specific Proteins ◽  
Meat Species ◽  
Species Specific

Consumer demand for both plant products and meat products enriched with plant raw materials is constantly increasing. Therefore, new versatile and reliable methods are needed to find and combat fraudulent practices in processed foods. The objective of this study was to identify oilseed species-specific peptide markers and meat-specific markers that were resistant to processing, for multispecies authentication of different meat and vegan food products using the proteomic LC-MS/MS method. To assess the limit of detection (LOD) for hemp proteins, cooked meatballs consisting of three meat species and hemp cake at a final concentration of up to 7.4% were examined. Hemp addition at a low concentration of below 1% was detected. The LOD for edestin subunits and albumin was 0.9% (w/w), whereas for 7S vicilin-like protein it was 4.2% (w/w). Specific heat-stable peptides unique to hemp seeds, flaxseed, nigella, pumpkin, sesame, and sunflower seeds, as well as guinea fowl, rabbit, pork, and chicken meat, were detected in different meat and vegan foods. Most of the oilseed-specific peptides were identified as processing-resistant markers belonging to 11S globulin subunits, namely conlinin, edestin, helianthinin, pumpkin vicilin-like or late embryogenesis proteins, and sesame legumin-like as well as 2S albumins and oleosin isoforms or selected enzymic proteins.

Specific binding of acrosome-reaction-inducing substance to the head of starfish spermatozoa

Zygote ◽  
1993 ◽  
Vol 1 (2) ◽  
pp. 121-127 ◽  
Author(s):  
Akira Ushiyama ◽  
Takeo Araki ◽  
Kazuyoshi Chiba ◽  
Motonori Hoshi
Keyword(s):  
Acrosome Reaction ◽  
Specific Binding ◽  
Molecular Size ◽  
Polystyrene Latex ◽  
Anterior Region ◽  
Head Region ◽  
Signal Molecule ◽  
Jelly Coat ◽  
Plot Analysis ◽  
Species Specific

In the starfish, spermatozoa undergo the acrosome reaction upon encountering the jelly coat of eggs. A highly sulphated glycoprotein in the jelly coat is called acrosome-reaction-inducing substance (ARIS) because it is the key signal molecule to trigger the acrosome reaction. The activity of ARIS is mainly attributed to its sulphate and saccharide residues. The extremely large molecular size and speciesspecific action of ARIS suggest the presence of a specific ARIS receptor on the sperm surface, but no experimental evidence for the receptor has been presented. We therefore measured specific binding of ARIS and its pronase digest (P-ARIS), which retains the full activity of ARIS, to homologous spermatozoa by using fluorescien-isothiocyanate-labelled ARIS and125 I-labelled P-ARIS, respectively. The spermatozoa had the ability to bind ARIS, as well as P-ARIS, specifically. The binding was species-specific, and mostly localised to the head region of spermatozoa. Scatchard plot analysis indicated the presence of one class of ARIS receptor on the surface of acrosome-intact speramatozoa. Furthermore, the specific binding of P-ARIS to the anterior region of sperm heads was microscopically confirmed by using P-ARIS conjugated to polystyrene latex beads with intense fluorescence. It is concluded that starfish spermatozoa have a specific receptor for ARIS on the surface of the anterior region of heads.

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.

scholarly journals Counter immunoelectrophoresis: a simple method for the detection of species-specific muscle proteins in heat-processed products

2012 ◽  
Vol 47 (No. 5) ◽  
pp. 143-147 ◽  
Author(s):  
L. Necidová ◽  
E. Renová ◽  
I. Svoboda
Keyword(s):  
Polyclonal Antibodies ◽  
Food Products ◽  
Muscular Tissue ◽  
Muscle Proteins ◽  
Simple Method ◽  
Commercial Products ◽  
Heat Stable ◽  
Specific Muscle ◽  
Processed Products ◽  
Species Specific

Counter immunoelectrophoresis (CIE) was used for the detection of species-specific muscle proteins in food products. This technique allowed the detection of pork, beef, poultry, or and kangaroo meats in heat-processed products at concentrations below 1.5%. CIE is based on the use of species-specific polyclonal antibodies prepared by immunisation of rabbits with heat-stable antigens extracted from visibly fat-free muscular tissue heated to 75°C, 100°C, or 120°C for 30 minutes. Adulterations in terms of declared product compositions were demonstrated by this method in 7 of the 50 tested commercial products.

Sign in / Sign up

Export Citation Format

Share Document