Elsevier

Developmental Biology

Volume 240, Issue 2, 15 December 2001, Pages 474-487
Developmental Biology

Regular Article
Roles for Zebrafish Focal Adhesion Kinase in Notochord and Somite Morphogenesis

https://doi.org/10.1006/dbio.2001.0467Get rights and content
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Abstract

We have cloned zebrafish focal adhesion kinase (Fak) and analyzed its subcellular localization. Fak protein is localized at the cortex of notochord cells and at the notochord–somite boundary. During somitogenesis, Fak protein becomes concentrated at the basal region of epithelial cells at intersomitic boundaries. Phosphorylated Fak protein is seen at both the notochord–somite boundary and intersomitic boundaries, consistent with a role for Fak in boundary formation and maintenance. The localization of Fak protein to the basal region of epithelial cells in knypek;trilobite double mutant embryos shows that polarization of Fak distribution in the somite border cells is independent of internal mesenchymal cells. In addition, we show that neither Notch signaling through Suppressor of Hairless (SuH) nor deltaD is necessary for the wild-type segmental pattern of fak mRNA expression in the anterior paraxial mesoderm. However, nonsegmental expression of fak mRNA occurs with ectopic activation of Notch signaling through SuH and also in fused somite and beamter mutant embryos, indicating that there are multiple regulators of fak mRNA expression. Our results suggest that Fak plays a central role in notochord and somite morphogenesis.

Keywords

focal adhesion kinase
phosphorylation
zebrafish
notochord
somitogenesis
Notch
knypek
trilobite
fused-somite

Cited by (0)

1

Present address: Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720.

2

To whom correspondence should be addressed. Fax: 206-543-3041. E-mail: [email protected].