...Mariya Broun; Lydia Gee; Beate Reinhardt; Hans R. Bode Stabilization of β-catenin by inhibiting the activity of glycogen synthase kinase-3β has been shown to initiate axis formation or axial patterning processes in many bilaterians. In hydra, the head organizer is located in the hypostome...

... head development by partially mimicking Lim1 mutants. Although the anterior visceral endoderm and the anterior definitive endoderm, which together comprise the head organizer, were able to form normally in Ssdp1 hsk/hsk mutants, development of the prechordal plate was compromised. Head development...

... the Xenopus central nervous system. *Author for correspondence (e-mail: [email protected] ) 2 8 2001 © 2001. 2001 Anteroposterior neuraxis AP β-catenin Gastrulation Head organizer Long-range signalling Morphogen gradient Neural patterning Neuroectoderm Nieuwkoop...

... movements around the time of gastrulation. We show that the hypoblast does not fit the criteria for a head organizer because it does not induce neural tissue from naÏve epiblast, nor can it change the regional identity of neural tissue. However, the hypoblast does induce transient expression of the early...

... Head organizer Otx2 Otx1 Visceral endoderm Rostral brain induction Brain regionalization Cephalic neural crest cells Isthmus Knock-in Homeobox Mouse The vertebrate head is a unique structure; no comparable structure is seen in cephalochordates or urochordates ( Balfour, 1881...

... extension movements. Trans- plantations of putative tail-forming regions showed that, while Xotx1 overexpression inhibits tail organizer activity, Xotx2 overexpression is able to turn a tail organizer into a head organizer. Finally, Xotx1 and Xotx2 are activated by factors involved in head formation...