Urchin eggs

In vivo labeling of sea urchin eggs revealed that fertilization results in an eightfold increase in 32P orthophosphate incorporation into tyrosine residues of egg proteins because of an increase in the activity of plasma membrane-bound tyrosine protein kinases (Ribot et al., 1984). Tyrosine phosphorylation is therefore believed to be an important step in the events following fertilization. 

Evans, T., Rosenthal, E. T Youngblom, J., Distel, D., and Hunt, T. (1983). Cyclin a protein specified by maternal mRNA in sea urchin eggs that is destroyed at each cleavage division. Cell 33 389-396. 

Pines, J., and Hunt, T. (1987). Molecular cloning and characterization of the mRNA for cyclin from sea urchin eggs. EMBO J. 6 2987-2995. 

Deoxy-L-galactose (L-fucose) HO H H HO HaC—C—C—C—C-—CHO H HO HO H plant gums seaweeds blood polysaccharides sea-urchin eggs frog-spawn mucin... 

Another naturally occurring quinone is echinochrome, a substance found in sea-urchin eggs.1 9... 

Kobayashi, N. 1971. Fertilized sea urchin eggs as an indicatory material for marine pollution bioassays, preliminary experiments. Publ. Seto Mar. Biol. Lab. 18 379-406. 

Kobayashi, N. and K. Fujinaga. 1976. Synergism of inhibiting actions of heavy metals upon the fertilization and development of sea urchin eggs. Sci. Engin. Rev. Doshisha Univ. 17 54-69. 

In echinoderms, zinc concentrations are usually higher in detrital feeders than in carnivores, higher in surface feeders than in sediment feeders, and higher in specimens collected inshore than those collected offshore in deeper waters (Eisler 1980). Sea cucumbers, Stichopus tremulus, accumulate radiozinc-65 from seawater by a factor of 1400 however, radiozinc accumulation data should be viewed with caution because addition of stable zinc can reduce zinc-65 accumulations in echinoderm viscera up to tenfold (Eisler 1981). Zinc inhibits the formation of the fertilization membrane in sea urchin eggs, possibly by interfering with cortical granule-derived proteases and proteins (Nakamura et al. 1989). 

Nakamura, S., C. Ohmi, and M.K. Kojima. 1989. Effect of zinc ion on formation of the fertilization membrane in sea urchin eggs. Zool. Sci. (Japan) 6 329-333. 

The inhibition of amino-acid transport has been regarded as the main toxic effect of mercury compounds [82], The biochemical mechanism underlying the inhibition is unclear. In unfertilized sea-urchin eggs an interaction with the amino-acid carrier was found, whereas in fertilized eggs inhibition of amino-acid transport was indirect and might result from an elevation of the Na + content of the egg caused by the inhibition of the Na+ pump [83]. The action on the diffusional process could be mediated by an effect on membrane phospholipids or on membrane proteins, or by interaction with Ca2+ which stabilizes membrane structure. Mercuric chloride in skate liver cells inhibited amino acid transport, decreased Na + /K + -ATPase (adenosinetriphosphatase) activity, impaired volume regulatory mechanisms and increased the permeability of the plasma membrane to potassium [84]. It has been suggested that... 

Salik, J., Herlands, L., Hoffmatm, H.P., and Poccia, D. (1981) Electrophoretic analysis of the stored histone pool in unfertilized sea urchin eggs quantification and identification by antibody binding. J. Cell Biol. 90, 385-395. 

One of the most impressive examples for the detection of a transcription factor was published in 1996, when a mobility-shift assay in a linear-polyacrylamide-filled capillary using fluorescein-labeled DNA showed 100 times higher sensitivity than the conventional slab-gel technique with 32P. Furthermore, the detection of a transcription factor in a single sea urchin egg was demonstrated (24). 

Sousa LMA, Neto, RLM, Schmidt FN, Oliveira MR. Anti-mitotic activity Towards Sea Urchin Eggs of Dichloromethane Fraction Obtained from Allamanda schottii Pohl (Apoc)naceae). Brazilian Journal of Pharmacognosy 2009 19(2A) 349-352. 

The repulsive, electrostatic forces of sialic acids contribute to the rigidity of the cell surface, as was shown hy an increase in the defor-mability of sarcoma cells after enzymic removal of sialic acid residues.424 Enzymic release of sialic acids from the zona pellucida of rabbit ovum lessens the rigidity of this cell, and spermatozoa can no longer penetrate it.425 Glycoproteins on the surface of sea-urchin eggs... 

Ratto, A. Christen, R. Purification and characterization of arginine kinase from sea-urchin eggs. Eur. J. Biochem., 173, 667-674 (1988)... 

Changes of internal pH during developmental events such as fertilization of sea urchin eggs (+0.3 unit) have been recorded. However, the significance of pH changes in metabolic regulation remains uncertain.0... 

Several uncertainties have complicated our understanding of the role of Ca2+ in signaling. What is the source of Ca2+ How much of it enters cells from the outside and how much is released from internal stores Where are the internal stores What other kinds of ion channels are present and what second messengers regulate them The sarcoplasmic reticulum of skeletal muscle and also membranes in many other cells contain ryanodine receptors as well as InsP3 receptors.282 293 Both of these receptors have similar structures and contain Ca2+ channels. However, the ryanodine receptors are activated by cyclic ADP ribose (cADPR),294/295 which was first discovered as a compound inducing the release of Ca2+ in sea urchin eggs.296 The 2-phospho derivative of cADPR may also have a similar function.297... 

A respiratory burst accompanies fertilization of sea urchin eggs.576 577 In this case, the burst appears to produce H202 as the major or sole product and is accompanied by release of ovoperoxidase from cortical granules. This enzyme uses H202 to generate dityrosine crosslinkages between tyrosine side chains during formation of the fertilization membrane. Defensive respiratory bursts are also employed by plant cells.578 579 See also Box 18-B. 

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