Regulation of early expression of Dlx3, a Xenopus anti-neural factor, by β-catenin signaling

The ectoderm of the pre-gastrula Xenopus embryo has previously been shown to be at least partially patterned along the dorsal-ventral axis. The early expression of the anti-neural homeodomain gene D1x3 is localized to the ventral ectoderm by a mechanism that occurs prior to gastrulation and is independent of the Spemann organizer. The repression of D1x3 is mediated by signaling though beta-catenin, but is probably not dependent on the induction of the Xnr3 or chordin genes by beta-catenin. We propose a model in which this early regulation of D1x3 accounts for the pro-neural bias of dorsal ectoderm. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.