Apical cell constriction during chicken lens placode invagination.

by Borges, Ricardo Moraes

Abstract (Summary)
Vertebrate lens derives from invagination of the ectoderm that overlies optic vesicles. Epithelial invagination in many model systems is driven by apical cell constriction, mediated by actin and myosin II contraction regulated by GTPase RhoA. Here we investigate the possibility that chick lens placode invagination could also be driven by apical cell constriction and controlled by RhoA. We show that actin and myosin II are expressed at lens apical side during lens invagination. Actin polymerization inhibition by in ovo Cytochalasin D treatment prevents lens placode invagination, suggesting that lens placode invagination could be driven by apical cell constriction. RhoA GTPase is also expressed at apical portion of lens placode and during lens invagination. However, when we overexpressed by electroporation the dominant-negative RhoA in the pre-lens ectoderm invagination was not affected. Furthermore, dominant-negative RhoA didnt affect myosin II apical localization nor myosin II phosphorilation, indicating that in lens invagination this process is not regulated by GTPase RhoA.
This document abstract is also available in Portuguese.
Bibliographical Information:

Advisor:Chao Yun Irene Yan; Ricardo Guelerman Pinheiro Ramos; Marinilce Fagundes dos Santos; Chao Yun Irene Yan

School:Universidade de São Paulo

School Location:Brazil

Source Type:Master's Thesis

Keywords:Apical cell constriction Epithelial invagination MorfogĂȘnese Morphogenesis Not muscle myosin II PlacĂłide the lens RhoA


Date of Publication:11/06/2008

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