scholarly journals Deciphering and modelling the TGF-β signalling interplays specifying the dorsal-ventral axis of the sea urchin embryo

2020 ◽  
Author(s):  
Swann Floc’hlay ◽  
Maria Dolores Molina ◽  
Céline Hernandez ◽  
Emmanuel Haillot ◽  
Morgane Thomas-Chollier ◽  
...  
Keyword(s):  
Sea Urchin ◽  
Organizer Region ◽  
Computational Modelling ◽  
Model Simulations ◽  
Mutual Antagonism ◽  
Regulatory Circuits ◽  
Sea Urchin Embryo ◽  
Bmp Pathway ◽  
Summary Statement ◽  
Ligand Diffusion

AbstractDuring sea urchin development, secretion of Nodal and BMP2/4 ligands and their antagonists Lefty and Chordin from a ventral organizer region specifies the ventral and dorsal territories. This process relies on a complex interplay between the Nodal and BMP pathways through numerous regulatory circuits. To decipher the interplay between these pathways, we used a combination of treatments with recombinant Nodal and BMP2/4 proteins and a computational modelling approach. We assembled a logical model focusing on cell responses to signalling inputs along the dorsal-ventral axis, which was extended to cover ligand diffusion and enable multicellular simulations. Our model simulations accurately recapitulate gene expression in wild type embryos, accounting for the specification of ventral ectoderm, ciliary band and dorsal ectoderm. Our model simulations further recapitulate various morphant phenotypes, reveals a dominance of the BMP pathway over the Nodal pathway, and stresses the crucial impact of the rate of Smad activation in D/V patterning. These results emphasise the key role of the mutual antagonism between the Nodal and BMP2/4 pathways in driving early dorsal-ventral patterning of the sea urchin embryo.Summary StatementWe propose a predictive computational model of the regulatory network controlling the dorsal-ventral axis specification in sea urchin embryos, and highlight key features of Nodal and BMP antagonism.

scholarly journals Deciphering and modelling the TGF-β signalling interplays specifying the dorsal-ventral axis of the sea urchin embryo

Development ◽  
2020 ◽  
pp. dev.189944
Author(s):  
Swann Floc'hlay ◽  
Maria Dolores Molina ◽  
Céline Hernandez ◽  
Emmanuel Haillot ◽  
Morgane Thomas-Chollier ◽  
...  
Keyword(s):  
Sea Urchin ◽  
Organizer Region ◽  
Computational Modelling ◽  
Model Simulations ◽  
Mutual Antagonism ◽  
Regulatory Circuits ◽  
Sea Urchin Embryo ◽  
Bmp Pathway ◽  
Ligand Diffusion

During sea urchin development, secretion of Nodal and BMP2/4 ligands and their antagonists Lefty and Chordin from a ventral organizer region specifies the ventral and dorsal territories. This process relies on a complex interplay between the Nodal and BMP pathways through numerous regulatory circuits. To decipher the interplay between these pathways, we used a combination of treatments with recombinant Nodal and BMP2/4 proteins and a computational modelling approach. We assembled a logical model focusing on cell responses to signalling inputs along the dorsal-ventral axis, which was extended to cover ligand diffusion and enable multicellular simulations. Our model simulations accurately recapitulate gene expression in wild type embryos, accounting for the specification of ventral ectoderm, ciliary band and dorsal ectoderm. Our model simulations further recapitulate various morphant phenotypes, reveals a dominance of the BMP pathway over the Nodal pathway, and stresses the crucial impact of the rate of Smad activation in D/V patterning. These results emphasise the key role of the mutual antagonism between the Nodal and BMP2/4 pathways in driving early dorsal-ventral patterning of the sea urchin embryo.

scholarly journals Functional Gap Junctions in the Early Sea Urchin Embryo Are Localized to the Vegetal Pole

1999 ◽  
Vol 212 (2) ◽  
pp. 503-510 ◽  
Author(s):  
Ikuko Yazaki ◽  
Brian Dale ◽  
Elisabetta Tosti
Keyword(s):  
Gap Junctions ◽  
Sea Urchin ◽  
Sea Urchin Embryo ◽  
Vegetal Pole

scholarly journals Exogenous hyalin and sea urchin gastrulation, Part II: hyalin, an interspecies cell adhesion molecule

Zygote ◽  
2008 ◽  
Vol 16 (1) ◽  
pp. 73-78 ◽  
Author(s):  
M. Alvarez ◽  
J. Nnoli ◽  
E.J. Carroll ◽  
V. Hutchins-Carroll ◽  
Z. Razinia ◽  
...  
Keyword(s):  
Sea Urchin ◽  
Cell Adhesion Molecule ◽  
Cellular Interaction ◽  
Adhesive Interaction ◽  
Lytechinus Pictus ◽  
Developmental Effects ◽  
Sea Urchin Embryo ◽  
Repeat Domain ◽  
Precise Quantification ◽  
Main Component

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.

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