1. Cell junctions during the early development of the sea urchin embryo (Paracentrotus lividus)
- Author
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Silvana Filosa, E. Parisi, Piero Andreuccetti, G. Cafiero, M. R. Barone Lumaga, Andreuccetti, P., Barone Lumaga, M. R., Cafiero, G., Filosa, S., and Parisi, E.
- Subjects
Intercellular bridge ,biology ,Cell division ,Gap junction ,Cleavage Stage, Ovum ,Septate junctions ,Cell Communication ,Cleavage (embryo) ,biology.organism_classification ,Cell junction ,Paracentrotus lividus ,Cell biology ,Microscopy, Electron ,Intercellular Junctions ,Cell–cell interaction ,Sea Urchins ,biology.animal ,Botany ,Cell-cell interaction ,Animals ,Freeze Fracturing ,Sea urchin embryo ,Sea urchin ,Cytokinesis ,Developmental Biology - Abstract
Thin sections, lanthanum tracer and the freeze-fracture technique revealed the presence of different types of cell junctions in early sea urchin (Paracentrotus lividus) embryos. During the first four cleavage cycles, which are characterized by synchrony of cell division, sister blastomeres were connected only by intercellular bridges, formed as a result of incomplete cytokinesis; no trace of other junctions was found at these stages. From the 16-cell stage onwards, septate junctions and gap junctions began to appear between blastomeres. It is postulated that cell-cell interactions may provide a mechanism for the propagation of signals necessary for the coordination of cell proliferation and differentiation.
- Published
- 1987
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