... Amphioxus Spemann organizer Embryonic axis Urbilateria Size scaling Evolution The evolution of animals, and specifically the relationships and lineages between extinct and extant species, is a central problem in biology ( Fig. 1 ). Related to it is a key question of evolutionary developmental...

... the ventralizing effects caused by loss of Chordin activity. Double Bmp4 and Bmp7 knockdown inhibited tail development. Triple Bmp2/Bmp4/Bmp7 depletion further compromised trunk development but did not eliminate dorsoventral patterning. Unexpectedly, we found that blocking Spemann organizer formation by UV...

...Ichiro Hiratani; Naoko Yamamoto; Toshiaki Mochizuki; Shin-ya Ohmori; Masanori Taira The Xenopus LIM homeodomain (LIM-HD) protein, Xlim-1, is expressed in the Spemann organizer and cooperates with its positive regulator, Ldb1, to activate organizer gene expression. While this activation...

... marginal cells can respond to Nodal signals at stages ranging from the mid-blastula through the mid-gastrula. † Author for correspondence (e-mail: [email protected] ) 9 1 2003 © 2003. 2003 Nodal signals Zebrafish Spemann organizer Gastrulation Dorsoventral axis...

...Hiroki Hikasa; Mikihito Shibata; Ichiro Hiratani; Masanori Taira The Spemann organizer plays a central role in neural induction, patterning of the neuroectoderm and mesoderm, and morphogenetic movements during early embryogenesis. By seeking genes whose expression is activated by the organizer...

... al., 1994 ; Zhang et al., 1998 ). In both cases, the Spemann organizer fails to form. Depletion of Xenopus maternal RNA encoding the GSK3-binding protein GBP also causes ventralization ( Yost et al., 1998 ). Since GBP inhibits GSK3 by preventing Axin from binding GSK3 ( Farr et al., 2000...

... dorsal repressor . Genes Dev . 10 , 2452 – 2461 . 10.1101/gad.10.19.2452 Harland , R and Gerhart , J. ( 1997 ). Formation and function of Spemann’s organizer . Annu. Rev. Cell Dev. Biol . 13 , 611 – 617 . 10.1146/annurev.cellbio.13.1.611 Holley , S...

[email protected] ; [email protected] ) 3 March 1998 28 December 1998 © 1999 by Company of Biologists 1999 Spemann organizer Nieuwkoop center Notochord Prechordal mesendoderm Dorsal forerunner cells A-P patterning bozozok Axis The key to understanding...

... role for vertebrate frizzleds has not yet been defined. To assess the endogenous role of frizzled proteins during vertebrate development, we have identified and characterized a Xenopus frizzled gene ( xfz8 ). It is highly expressed in the deep cells of the Spemann organizer prior to dorsal lip...

... node Primitive streak Spemann organizer The molecular bases of gastrulation and neural induction remain poorly understood in amniote embryos, and much of what we know about these processes in vertebrates is derived from studies of anuran amphibians. One of the key events during amniote...

... patterning Nieuwkoop Center Spemann Organizer growth factor signal transduction Siamois Xenopus Wnt β-catenin Activin Noggin Determination of the dorsoventral axis in Xenopus eggs occurs at fertilization by an asymmetric redistribution of an unknown determinant within the vegetal pole...

... nodal noggin Xenopus neural induction Spemann organizer The vertebrate body axis is elaborated as a result of extensive changes in cell movement and tissue specification that occur during gastrulation. Of particular importance in directing mor-phogenesis and tissue formation during...

... control the main functions of cells of the Spemann organizer. * Author for correspondence (e-mail: [email protected] ) 15 08 1995 © 1995 by Company of Biologists 1995 XANF-1 may also control another important property of cells of the presumptive anterior mesoderm, namely...

... suggests that the effects of Xgsk-3K→R are mediated by an additional intercellular signal. * Author for correspondence 07 11 1994 © 1995 by Company of Biologists 1995 Xenopus Spemann organizer kinase XGSK-3 dorsal axis formation Wnt Our results are consistent...

... tail, a structure characteris tic of the chordates. * Author for correspondence © 1994 by Company of Biologists 1994 Spemann organizer tailbud goosecoid Brachyury Xnot-2 gastrulation Evolutionary and embryological studies have been intertwined throughout their history...

... in a specific dorsal midline, animal blastomere (D1.1) of the 16-cell-stage embryo. This blastomere, although in the animal hemisphere at cleavage stages, populates most of the dorsal lip of the blastopore, the region of Spemann’s organizer, during gastrulation, and is the major progenitor for dorsal mesodermal...