1. Department of Molecular and Cell Biology, 401 Barker Hall, University of California, Berkeley, California 94720-3204, USA
2. Life Sciences Division (MS6-2100), Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
3. Division of Biology and Beckman Institute, California Institute of Technology, Pasadena, California 91125, USA
4. Present address: Labouratoire de Genetique et Physiologie du Development, IBDM, Campus de Luminy, Marseille, France

Correspondence to: Richard M. Harland¹ Correspondence and requests for materials should be addressed to R.M.H. (e-mail: Email: harland@socrates.berkeley.edu).

Abstract

Although cell movements are vital for establishing the normal architecture of embryos, it is unclear how these movements are regulated during development in vertebrates. Inhibition of Xenopus Dishevelled (Xdsh) function disrupts convergent extension movements of cells during gastrulation, but the mechanism of this effect is unclear, as cell fates are not affected¹. In Drosophila, Dishevelled controls both cell fate and cell polarity^{2, 3, 4}, but whether Dishevelled is involved in controlling cell polarity in vertebrate embryos has not been investigated. Here we show, using time-lapse confocal microscopy, that the failure of cells lacking Xdsh function to undergo convergent extension results from defects in cell polarity. Furthermore, Xdsh mutations that inhibit convergent extension correspond to mutations in Drosophila Dishevelled that selectively perturb planar cell polarity. Finally, the localization of Xdsh at the membrane of normal dorsal mesodermal cells is consistent with Xdsh controlling cell polarity. Our results show that polarized cell behaviour is essential for convergent extension and is controlled by vertebrate Dishevelled. Thus, a vertebrate equivalent of the Drosophila planar cell polarity signalling cascade may be required for normal gastrulation.