Developmental changes in amounts of sulfhydryl-agent decolorant released by sea urchin embryos

1974 ◽  
Vol 52 (12) ◽  
pp. 1531-1534
Author(s):  
N. Wolfson
Keyword(s):  
Sea Urchin ◽  
Paracentrotus Lividus ◽  
Tris Buffer ◽  
Developmental Changes ◽  
Cell Stage ◽  
Nitrobenzoic Acid ◽  
Sea Urchin Embryos ◽  
Saline Medium

Live embryos of the sea urchin, Paracentrotus lividus, release materials which decolor the yellow ion formed by the reagent DTNB (5,5′-dithiobis(2-nitrobenzoic acid)) in amounts titratable with dithiothreitol, and this decolorant activity increased to about the 32-cell stage, declining gradually thereafter. The embryos release decolorants into a saline medium only if it contains Tris buffer and little or no calcium and is adjusted to a pH below 8.

A decolorant of the sulfhydryl reagent DTNB released from live blastulae of sea urchins in saline medium

Development ◽  
1972 ◽  
Vol 28 (3) ◽  
pp. 511-519
Author(s):  
N. Wolfson
Keyword(s):  
Sea Urchin ◽  
Sea Urchins ◽  
Paracentrotus Lividus ◽  
Blastula Stage ◽  
Sulfhydryl Reagent ◽  
Nitrobenzoic Acid ◽  
Saline Medium

Cleaving embryos of the sea urchin Paracentrotus lividus exposed briefly to buffered saline release materials into the medium which will bleach a yellow mixture of DTNB and DTT [5,5'-dithiobis (2-nitrobenzoic acid) and dithiothreitol]. The decolorant activity is thermolabile and dialysable. The bleached mixture recolors rapidly on heating, suggesting the breakdown of a complex between the decolorant and the yellow DTNB ion. The release of decolorants is maximal at the blastula stage, and in Ca-free saline, Tris-HCl pH 7. When various untreated embryonic stages are homogenized with DTNB, the assay for SH is lowest at blastula, suggesting that decolorants in the blastulae interfere with the assay.

scholarly journals SYNTHESIS AND STORAGE OF MICROTUBULE PROTEINS BY SEA URCHIN EMBRYOS

1971 ◽  
Vol 50 (2) ◽  
pp. 516-528 ◽  
Author(s):  
Rudolf A. Raff ◽  
Gerald Greenhouse ◽  
Kenneth W. Gross ◽  
Paul R. Gross
Keyword(s):  
Amino Acids ◽  
Sea Urchin ◽  
Messenger Rna ◽  
Binding Activity ◽  
Total Soluble Protein ◽  
Cell Stage ◽  
Lytechinus Pictus ◽  
Sea Urchin Embryos ◽  
Tritiated Amino Acids ◽  
Vinblastine Sulfate

Studies employing colchicine binding, precipitation with vinblastine sulfate, and acrylamide gel electrophoresis confirm earlier proposals that Arbacia punctulata and Lytechinus pictus eggs and embryos contain a store of microtubule proteins. Treatment of 150,000 g supernatants from sea urchin homogenates with vinblastine sulfate precipitates about 5% of the total soluble protein, and 75% of the colchicine-binding activity. Electrophoretic examination of the precipitate reveals two very prominent bands. These have migration rates identical to those of the A and B microtubule proteins of cilia. These proteins can be made radioactive at the 16 cell stage and at hatching by pulse labeling with tritiated amino acids. By labeling for 1 hr with leucine-3H in early cleavage, then culturing embryos in the presence of unlabeled leucine, removal of newly synthesized microtubule proteins from the soluble pool can be demonstrated. Incorporation of labeled amino acids into microtubule proteins is not affected by culturing embryos continuously in 20 µg/ml of actinomycin D. Microtubule proteins appear, therefore, to be synthesized on "maternal" messenger RNA. This provides the first protein encoded by stored or "masked" mRNA in sea urchin embryos to be identified.

Incorporation of Uridine in Cleavage Stage Eggs of the Sea Urchin Paracentrotus Lividus

1971 ◽  
Vol 26 (8) ◽  
pp. 816-821 ◽  
Author(s):  
Larry E. Bockstahler
Keyword(s):  
Ion Exchange ◽  
Sea Urchin ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Paracentrotus Lividus ◽  
Cleavage Stage ◽  
Early Cleavage ◽  
Cell Stage ◽  
Cleavage Stages ◽  
Layer Chromatography

Incorporation of uridine in cleavage stage eggs of the sea urchin Paracentrotus lividus was investigated. It was shown by ion exchange and thin layer chromatography that most of the uridine taken up during the 16-cell stage was converted into UTP with some incorporation into UDP and UMP. Conversion of uridine to these phosphorylated nucleosides occurred throughout early cleavage stages. A very small amount of uridine taken up by cleavage stage eggs is incorporated into RNA heterogeneous in size. This RNA was examined by polyacrylamide gel electrophoresis.

scholarly journals ADP-ribosyltransferase in isolated nuclei from sea-urchin embryos

1985 ◽  
Vol 225 (2) ◽  
pp. 429-434 ◽  
Author(s):  
A Isoai ◽  
I Yasumasu
Keyword(s):  
Sea Urchin ◽  
Insoluble Fraction ◽  
Cell Stage ◽  
Isolated Nuclei ◽  
Sea Urchin Embryos ◽  
Snake Venom Phosphodiesterase ◽  
Km Value ◽  
Insoluble Product ◽  
Adp Ribosyltransferase ◽  
Hydrolysis Of

The activity of ADP-ribosyltransferase in nuclei isolated from sea-urchin embryos was estimated by the incorporation of [adenosine-14C]NAD+ into the acid-insoluble fraction. Hydrolysis of this acid-insoluble product by snake venom phosphodiesterase yielded radioactive 5′-AMP and phosphoribosyl-AMP. The incorporation of [14C]-NAD+ was inhibited by 3-aminobenzamide and nicotinamide, potent inhibitors of ADP-ribosyltransferase. [14C]NAD+ incorporation into the acid-insoluble fraction results from the reaction of ADP-ribosyltransferase. The optimum pH for the enzyme in isolated nuclei was 7.5. The enzyme, in 50 mM-Tris/HCl buffer, pH 7.5, containing 0.5 mM-NAD+ and 0.5 mM-dithiothreitol, exhibited the highest activity at 18 degrees C in the presence of 14 mM-MgCl2. The apparent Km value for NAD+ was 25 microM. The activity of the enzyme was measured in nuclei isolated from the embryos at several stages during early development. The activity was maximum at the 16-32-cell stage and then decreased to a minimum at the mesenchyme blastula stage. Thereafter its activity slightly increased at the onset of gastrulation and decreased again at the prism stage.

scholarly journals Amino Acid Composition of Collagen Extracted from the Spicules of Sea-Urchin Embryos (Paracentrotus Lividus)

1975 ◽  
Vol 42 (2-3) ◽  
pp. 201-204 ◽  
Author(s):  
Ida Pucci-Minafra ◽  
Salvatore Minafra ◽  
Fabrizio Gianguzza ◽  
Caterina Casano
Keyword(s):  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Sea Urchin ◽  
Paracentrotus Lividus ◽  
Sea Urchin Embryos

Polarized distribution of L-type calcium channels in early sea urchin embryos

1997 ◽  
Vol 273 (3) ◽  
pp. C822-C825 ◽  
Author(s):  
B. Dale ◽  
I. Yazaki ◽  
E. Tosti
Keyword(s):  
Steady State ◽  
Calcium Channels ◽  
Sea Urchin ◽  
Calcium Currents ◽  
Cleavage Division ◽  
Cell Stage ◽  
Developmental Defects ◽  
Calcium Dependent ◽  
Sea Urchin Embryos ◽  
M Phase

Using the whole cell clamp technique, we have measured calcium-dependent currents and steady-state conductance in early sea urchin blastomeres. The calcium currents in M phase decreased from 8.5 microA/cm2 at the four-cell stage to 5.4 microA/cm2 at the eight-cell stage. In 16-cell stage embryos, calcium currents were 7.4 microA/cm2 in the mesomeres, 2.3 microA/cm2 in the macromeres, and were not detected in the micromeres. In contrast, the micromeres had a two- to threefold higher steady-state conductance than the mesomeres or macromeres, which may be due to potassium ion conductivity. Nifedipine, an L-type channel antagonist, delays cleavage division at a concentration of 0.05-0.1 mM and causes developmental defects, such as poor skeletal differentiation in later sea urchin embryos.

Free choline in sea urchin embryos (Paracentrotus lividus)

1977 ◽  
Vol 33 (1) ◽  
pp. 38-39
Author(s):  
N. Wolfson ◽  
M. Acara ◽  
B. Rennick
Keyword(s):  
Sea Urchin ◽  
Paracentrotus Lividus ◽  
Sea Urchin Embryos ◽  
Free Choline
Sign in / Sign up

Export Citation Format

Share Document