Asymmetric distribution of Echinoid defines the epidermal leading edge during Drosophila dorsal closure
نویسندگان
چکیده
During Drosophila melanogaster dorsal closure, lateral sheets of embryonic epidermis assemble an actomyosin cable at their leading edge and migrate dorsally over the amnioserosa, converging at the dorsal midline. We show that disappearance of the homophilic cell adhesion molecule Echinoid (Ed) from the amnioserosa just before dorsal closure eliminates homophilic interactions with the adjacent dorsal-most epidermal (DME) cells, which comprise the leading edge. The resulting planar polarized distribution of Ed in the DME cells is essential for the localized accumulation of actin regulators and for actomyosin cable formation at the leading edge and for the polarized localization of the scaffolding protein Bazooka/PAR-3. DME cells with uniform Ed fail to assemble a cable and protrude dorsally, suggesting that the cable restricts dorsal migration. The planar polarized distribution of Ed in the DME cells thus provides a spatial cue that polarizes the DME cell actin cytoskeleton, defining the epidermal leading edge and establishing its contractile properties.
منابع مشابه
Asymmetric distribution of Echinoid defines the epidermal leading edge during Drosophila dorsal
The Rockefeller University Press $30.00 J. Cell Biol. Vol. 192 No. 2 335–348 www.jcb.org/cgi/doi/10.1083/jcb.201009022 JCB 335 Correspondence to Laura A. Nilson: [email protected] Caroline Laplante’s present address is Dept. of Molecular, Cell, and Developmental Biology, Yale University, New Haven, CT 06520. Abbreviations used in this paper: ANC, actin-nucleating center; AP, anterior– post...
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