Organization of the ciliary basal apparatus in embryonic cells of the sea urchin, Lytechinus pictus

1992 ◽  
Vol 269 (2) ◽  
pp. 305-313 ◽  
Author(s):  
John A. Anstrom
Development ◽  
1988 ◽  
Vol 104 (3) ◽  
pp. 391-402 ◽  
Author(s):  
D.L. Adelson ◽  
T. Humphreys

We have generated and characterized a monoclonal antibody (McA Tg-HYL) that recognizes sea urchin hyalin as evidenced by immunofluorescence staining of the hyaline layer (HL) and immunoblot staining of the hyalin protein band. On immunoblots of HL extracts only the hyalin protein reacted with McA Tg-HYL. Immunoprecipitates of radioactive proteins from embryos incubated with [35S]methionine yielded radioactive hyalin and 190, 140 and 105 × 10(3) Mr proteins associated with hyalin. McA Tg-HYL was generated against Tripneustes gratilla embryos but reacts with hyalin from the distantly related sea urchin species, Colobocentrotus atratus, Strongylocentrotus purpuratus, Arbacia punctulata, Lytechinus variegatus and Lytechinus pictus. Developing embryos of the above-mentioned six species were treated with McA Tg-HYL and did not gastrulate or form arms. Observations of treated embryos revealed areas of separation of the hyaline layer from the underlying embryonic cells, suggesting that McA Tg-HYL was interfering with binding of the cells to the HL. Using the centrifugation-based adhesion assay of McClay et al. (Proc. natn. Acad. Sci. U.S.A. 78, 4975–4979, 1981), Fab' fragments of McA Tg-HYL were found to inhibit cell-hyalin binding. McA Tg-HYL did not inhibit hyalin gelation in vitro or the reaggregation of dissociated blastula cells. We postulate that McA Tg-HYL recognizes an evolutionarily conserved hyalin domain involved in cell-hyalin binding and required for normal epithelial folding.


2012 ◽  
Vol 8 (6) ◽  
pp. 1003-1011
Author(s):  
Jocelmo C. A. Leite ◽  
Claudio G. L. Junior ◽  
Fabio P. L. Silva ◽  
Suervy C.O. Sousa ◽  
Mario L. A. A. Vasconcellos ◽  
...  

1981 ◽  
Vol 256 (24) ◽  
pp. 13105-13111
Author(s):  
G.R. Mintz ◽  
S DeFrancesco ◽  
W.J. Lennarz

1971 ◽  
Vol 50 (2) ◽  
pp. 516-528 ◽  
Author(s):  
Rudolf A. Raff ◽  
Gerald Greenhouse ◽  
Kenneth W. Gross ◽  
Paul R. Gross

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.


Zygote ◽  
2008 ◽  
Vol 16 (1) ◽  
pp. 73-78 ◽  
Author(s):  
M. Alvarez ◽  
J. Nnoli ◽  
E.J. Carroll ◽  
V. Hutchins-Carroll ◽  
Z. Razinia ◽  
...  

SummaryThe 330 kDa fibrillar glycoprotein hyalin is a well known component of the sea urchin embryo extracellular hyaline layer. Only recently, the main component of hyalin, the hyalin repeat domain, has been identified in organisms as widely divergent as bacteria and humans using the GenBank database and therefore its possible function has garnered a great deal of interest. In the sea urchin, hyalin serves as an adhesive substrate in the developing embryo and we have recently shown that exogenously added purified hyalin from Strongylocentrotus purpuratus embryos blocks a model cellular interaction in these embryos, archenteron elongation/attachment to the blastocoel roof. It is important to demonstrate the generality of this result by observing if hyalin from one species of sea urchin blocks archenteron elongation/attachment in another species. Here we show in three repeated experiments, with 30 replicate samples for each condition, that the same concentration of S. purpuratus hyalin (57 μg/ml) that blocked the interaction in living S. purpuratus embryos blocked the same interaction in living Lytechinus pictus embryos. These results correspond with the known crossreactivity of antibody against S. purpuratus hyalin with L. pictus hyalin. We propose that hyalin–hyalin receptor binding may mediate this adhesive interaction. The use of a microplate assay that allows precise quantification of developmental effects should help facilitate identification of the function of hyalin in organisms as divergent as bacteria and humans.


1997 ◽  
Vol 200 (22) ◽  
pp. 2881-2892 ◽  
Author(s):  
P Leong ◽  
D Manahan

Early stages of animal development have high mass-specific rates of metabolism. The biochemical processes that establish metabolic rate and how these processes change during development are not understood. In this study, changes in Na+/K+-ATPase activity (the sodium pump) and rate of oxygen consumption were measured during embryonic and early larval development for two species of sea urchin, Strongylocentrotus purpuratus and Lytechinus pictus. Total (in vitro) Na+/K+-ATPase activity increased during development and could potentially account for up to 77 % of larval oxygen consumption in Strongylocentrotus purpuratus (pluteus stage) and 80 % in Lytechinus pictus (prism stage). The critical issue was addressed of what percentage of total enzyme activity is physiologically active in living embryos and larvae and thus what percentage of metabolism is established by the activity of the sodium pump during development. Early developmental stages of sea urchins are ideal for understanding the in vivo metabolic importance of Na+/K+-ATPase because of their small size and high permeability to radioactive tracers (86Rb+) added to sea water. A comparison of total and in vivo Na+/K+-ATPase activities revealed that approximately half of the total activity was utilized in vivo. The remainder represented a functionally active reserve that was subject to regulation, as verified by stimulation of in vivo Na+/K+-ATPase activity in the presence of the ionophore monensin. In the presence of monensin, in vivo Na+/K+-ATPase activities in embryos of S. purpuratus increased to 94 % of the maximum enzyme activity measured in vitro. Stimulation of in vivo Na+/K+-ATPase activity was also observed in the presence of dissolved alanine, presumably due to the requirement to remove the additional intracellular Na+ that was cotransported with alanine from sea water. The metabolic cost of maintaining the ionic balance was found to be high, with this process alone accounting for 40 % of the metabolic rate of sea urchin larvae (based on the measured fraction of total Na+/K+-ATPase that is physiologically active in larvae of S. purpuratus). Ontogenetic changes in pump activity and environmentally induced regulation of reserve Na+/K+-ATPase activity are important factors that determine a major proportion of the metabolic costs of sea urchin development.


Development ◽  
1995 ◽  
Vol 121 (5) ◽  
pp. 1497-1505 ◽  
Author(s):  
A.H. Wikramanayake ◽  
B.P. Brandhorst ◽  
W.H. Klein

During early embryogenesis, the highly regulative sea urchin embryo relies extensively on cell-cell interactions for cellular specification. Here, the role of cellular interactions in the temporal and spatial expression of markers for oral and aboral ectoderm in Strongylocentrotus purpuratus and Lytechinus pictus was investigated. When pairs of mesomeres or animal caps, which are fated to give rise to ectoderm, were isolated and cultured they developed into ciliated embryoids that were morphologically polarized. In animal explants from S. purpuratus, the aboral ectoderm-specific Spec1 gene was activated at the same time as in control embryos and at relatively high levels. The Spec1 protein was restricted to the squamous epithelial cells in the embryoids suggesting that an oral-aboral axis formed and aboral ectoderm differentiation occurred correctly. However, the Ecto V protein, a marker for oral ectoderm differentiation, was detected throughout the embryoid and no stomodeum or ciliary band formed. These results indicated that animal explants from S. purpuratus were autonomous in their ability to form an oral-aboral axis and to differentiate aboral ectoderm, but other aspects of ectoderm differentiation require interaction with vegetal blastomeres. In contrast to S. purpuratus, aboral ectoderm-specific genes were not expressed in animal explants from L. pictus even though the resulting embryoids were morphologically very similar to those of S. purpuratus. Recombination of the explants with vegetal blastomeres or exposure to the vegetalizing agent LiCl restored activity of aboral ectoderm-specific genes, suggesting the requirement of a vegetal induction for differentiation of aboral ectoderm cells.(ABSTRACT TRUNCATED AT 250 WORDS)


1991 ◽  
Vol 71 (3) ◽  
pp. 289-291 ◽  
Author(s):  
Valeria Matranga ◽  
Daniela Ferro ◽  
Melchiorre Cervello ◽  
Francesca Zito ◽  
Eizo Nakano

1991 ◽  
Vol 148 (2) ◽  
pp. 473-480 ◽  
Author(s):  
Brian T. Livingston ◽  
Robin Shaw ◽  
Adina Bailey ◽  
Fred Wilt
Keyword(s):  

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