Differential tissue expression of a calpastatin isoform in Xenopus embryos
| Autor: | A. M. Fausto, S. Marracci, Antonella Cecchettini, I. Nardi, C. Di Primio, Massimo Mazzini, Franco Giorgi, Gabriella Gambellini |
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| Přispěvatelé: | DI PRIMIO, Cristina, S., Marracci, A., Cecchettini, Nardi, I, F., Giorgi, A. M., Fausto, G., Gambellini, M., Mazzini |
| Rok vydání: | 2006 |
| Předmět: |
Gene isoform
Cytoplasm Embryo Nonmammalian Immunoblotting Xenopus Notochord General Physics and Astronomy Vacuole Myoblasts Xenopus laevis Microscopy Electron Transmission Structural Biology medicine Animals Protein Isoforms General Materials Science Enzyme Inhibitors Calpastatin Microscopy Confocal biology Calpain Calcium-Binding Proteins Cell Biology Dipeptides biology.organism_classification Molecular biology Immunohistochemistry Cell biology Somite medicine.anatomical_structure Somites Vacuoles biology.protein Microscopy Electron Scanning |
| Zdroj: | Micron (Oxford, England : 1993). 38(3) |
| ISSN: | 0968-4328 |
| Popis: | This study is aimed at demonstrating the role played by a calpastatin isoform (Xcalp3) in Xenopus embryos. A specific monoclonal antibody (mAb) was raised against a glutathioneS-transferase (GST)-Xcalp3 fusion protein and characterized byimmunoblotting and confocalfluorescence microscopy on stage 20‐36 embryos. Under these conditions, calpastatin reactivity is associated with a major 110 kDa protein fraction and preferentially expressed by notochord and somitic cells. In notochord cells, anti-calpastatin reactive sites were initially restricted to the luminal space of the vacuoles and later became diffused throughout the cytoplasm. In contrast, anti-calpastatin reactive sites in somitic cells were initially diffused throughout the cytoplasm and became restricted to a few intracellular granules in the later developmental stages. At the ultrastructural level, notochord cells appeared as flattened discs containing several vacuoles and numerous electron-dense granules. During transition from stages 26 to 32, electron-dense granules were gradually reduced in number as vacuoles enlarged in size and losed their calpastatin reactivity. Electron-dense granules were also present in myoblast cells and their number gradually reduced during development. To determinewhether these observations bear any causal relationship to the calpain/calpastatin system, a number of Xenopus embryos were examined both ultrastructurally and histochemically following exposure to a specific calpain inhibitor (CI3). Under these conditions, Xenopus embryos exhibitedan altered right-left symmetry and an abnormalaxial shortening.In CI3-treated stage 32embryos, notochordcells had a reducedvacuolar extension and exhibited at the same time an increase in granular content. The overall morphology of the somites was also distorted and myoblasts were altered both in shape and granular content. Based on these findings, it is concluded that the calpain/calpastatin may play an important role in the control of notochord elongation and somite differentiation during Xenopus embryogenesis. # 2006 Elsevier Ltd. All rights reserved. |
| Databáze: | OpenAIRE |
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