scholarly journals Electrophoretic movement of fertilized sea-urchin eggs

1982 ◽  
Vol 55 (1) ◽  
pp. 105-113
Author(s):  
N. Oshima
Keyword(s):  
Electric Field ◽  
Surface Charge ◽  
Electrophoretic Mobility ◽  
Sea Urchin ◽  
Egg Cell ◽  
Migration Speed ◽  
Protamine Sulphate ◽  
Sea Urchin Egg ◽  
Fertilization Membrane ◽  
Whole Egg

The eccentric shift of the sea-urchin egg within the fertilization membrane under an electric field was analysed by measuring the electrophoretic mobility of the isolated fertilization membrane and that of the egg deprived of the fertilization membrane. In addition, the migration speed of the egg proper was measured within the fertilization membrane under the conditions that: either (1) the movement of the whole egg was arrested, or (2) protamine sulphate was adsorbed on the fertilization membrane to reduce its mobility. The results led to conclusions that: (1) both the fertilization membrane and the egg cell with the hyaline layer are negatively charged; (2) movement of the normal fertilized eggs is due mainly to the surface charge of the fertilization membrane; and (3) the eccentric position of the egg within the fertilization membrane is due to migration of the egg proper, which is independent of the movement of the whole egg.

Isolated Plasma Membranes of Sea Urchin Eggs

1971 ◽  
Vol 29 ◽  
pp. 534-535
Author(s):  
S. Inoue ◽  
E. C. Preddie ◽  
P. Guerrier
Keyword(s):  
Electron Microscope ◽  
Sea Urchin ◽  
Plasma Membranes ◽  
Membrane System ◽  
Vitelline Membrane ◽  
Thin Sections ◽  
Sea Urchin Eggs ◽  
Sea Urchin Egg ◽  
Discontinuous Sucrose Gradient ◽  
Fertilization Membrane

From electron microscope studies of thin sections the sea urchin egg is known to be surrounded by the peripheral membrane system which is made up of the outer coat (vitelline membrane), which elevates from an egg surface after fertilization and becomes a part of the fertilization membrane, and the plasma membrane. In these experiments an effort has been made to isolate plasma membranes of sea urchin eggs and these isolated membranes were observed in the electron microscope.The vitelline membrane of the eggs from the sea urchin Strongylocentrotus purpuratus was at first digested away by the treatment with 0.02% trypsin in 0.01 M Tris-HCl buffer (pH 8.0) for 5 minutes at 28°C. The plasma membranes were then isolated according to the method of Song et al. which was used for the isolation of rat liver plasma membranes. The vitelline membrane-free eggs were gently homogenized in 10-3 M NaHC03 (pH 7.5) and freed membranes were collected by centrifugation over a discontinuous sucrose gradient preparation.

Mechanism of Formation of the Fertilization Membrane in the Sea Urchin Egg

Nature ◽  
1944 ◽  
Vol 153 (3880) ◽  
pp. 313-314 ◽  
Author(s):  
JOHN RUNNSTRÖM ◽  
LUDWIK MONNÉ ◽  
ELSA WICKLUND
Keyword(s):  
Sea Urchin ◽  
Mechanism Of Formation ◽  
Sea Urchin Egg ◽  
Fertilization Membrane

scholarly journals A localized zone of increased conductance progresses over the surface of the sea urchin egg during fertilization.

1991 ◽  
Vol 97 (3) ◽  
pp. 579-604 ◽  
Author(s):  
D H McCulloh ◽  
E L Chambers
Keyword(s):  
Patch Clamp ◽  
Sea Urchin ◽  
Membrane Conductance ◽  
Phase 2 ◽  
Opposite Pole ◽  
Sea Urchin Egg ◽  
Conductance Changes ◽  
Conductance Increase ◽  
Membrane Patch ◽  
Whole Egg

Although activation of a sea urchin egg by sperm leads to three phases of membrane conductance increase in the egg, the mechanism by which the sperm causes these conductance changes is not known. We used the loose patch clamp technique to localize the conductance changes in voltage clamped eggs. A patch of the egg's membrane was isolated from the bath by pressing the loose patch clamp pipette against the egg surface. Sperm added to the bath attached to the surface of the egg in a region other than at the isolated membrane patch. During phase 1 of the activation current, no changes of the membrane conductance were detected. At the time of, and subsequent to the onset of phase 2, large currents recorded between the interior of the patch pipette and the bath were attributed to changes of the seal resistance between the surface of the egg and the pipette. A local change of membrane conductance was observed during phase 2 despite the changes of seal resistance. During phase 2, the large amplitude and short duration of the local membrane conductance increase relative to the membrane, conductance increase for the whole egg during phase 2 indicated that the conductance increase occurred over the entire surface of the egg, but not simultaneously. The time when the peak conductance for the membrane patch occurred, relative to the time of onset for phase 2 in the whole egg, depended on the distance, measured in a straight line, between the site of sperm attachment and the tip of the pipette. These data indicate that the localized conductance increase progressed over the surface of the egg from the site of sperm attachment to the opposite pole of the egg. It is proposed that the local conductance increase, the cortical reaction, and the change of seal resistance are all evoked by a common cytoplasmic message that progresses throughout the cytoplasm of the egg from the site of sperm attachment to the opposite pole of the egg.

Stereoselective synthesis of a 9-O-sulfo Neu5Gc-capped O-linked oligosaccharide found on the sea urchin egg receptor

2019 ◽  
Vol 6 (1) ◽  
pp. 54-61 ◽  
Author(s):  
Anindya Das ◽  
Pei-Jhen Li ◽  
Avijit K. Adak ◽  
Hsin-Ru Wu ◽  
Mohammad Tarique Anwar ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Sea Urchin ◽  
Stereoselective Synthesis ◽  
Egg Cell ◽  
Cell Surfaces ◽  
Sea Urchin Egg

The first total synthesis of a serine bearing α2→5-Oglycolyl-linked oligoNeu5Gc found on sea urchin egg cell surfaces has been accomplished.

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