Sato Y , Narasaki I , Kunimoto T , Moriyama Y , Hashimoto C .

	Fig. 2 ACE embryo lacking blastocoel roof and ventral two-thirds of the marginal zone developed the complete dorsal structures. a Schematic drawing of removal of the blastocoel roof and the ventral marginal zone at ACE. b The ACE embryo after removal of the blastocoel roof and ventral marginal zone. c The percentage of the embryo with dorsal structure after the removal of the indicated amount of the vegetal marginal zone at ACE. d, e The tailbud embryos developed from control and operated ACE embryo. Scale bars, 1 mm. f–y In situ hybridization of control and operated embryos. Scale bars, 500 µm. The expression of bf1 (f, g), otx2 (h, i), rx2a (j, k), pax6 (l, m), krox20 (n, o), hairy2 (p, q), gsc (r, s), and chd (t, u) in the neurula stage. The expression of myoD (v, w) and bra (x, y) in the tailbud stage
	Fig. 3 ACE embryo lacking yolky endoderm developed the complete dorsal structures. a Schematic drawing of the yolky endoderm removal at ACE. b, c The tailbud embryos developed from control and operated ACE embryo. Scale bars, 1 mm. d–w In situ hybridization of control and operated embryos. Scale bars, 500 µm. The expression of bf1 (d, e), otx2 (f, g), rx2a (h, i), pax6 (j, k), krox20 (l, m), hairy2 (n, o), gsc (p, q), and chd (r, s) in the neurula stage. The expression of myoD (t, u) and bra (v, w) in the tailbud stage
	Fig. 4 Transplantation of mGFP-labeled dorsal marginal zone at ACE into the ventral side of non-labeled ACE embryo. a Schematic drawing of the transplantation assay. b The whole-mount view of operated embryo at the tailbud stage. White arrowheads, mGFP-labeled secondary body axis. c The transverse section of head in the secondary body axis. White arrowhead, neural tube. Black arrowheads, eyes. d The transverse section of trunk region in the secondary body axis. White arrowhead, neural tube. Black arrowhead, notochord
	Fig. 5 The explant of blastocoel roof of blastula developed an embryo only lacking yolk mass. a Schematic drawing of the blastocoel roof explant of blastula. b, c The tailbud embryos developed from control and operated blastocoel roof explant of blastula. Scale bars, 1 mm
	Supplementary Fig. 1 Transplantation of non-labeled dorsal marginal zone at ACE into the ventral side of mGFP-labeled ACE embryo. (a) Schematic drawing of the transplantation assay. (b) The lateral view of the operated embryo at tailbud stage. The non-labeled secondary body axis was formed at the ventral side. (c) The ventral view of the operated embryo. The head and the tail of the secondary body axis were completely non-labeled.
	Supplementary Fig. 2 The explant of dorsal marginal zone at ACE developed into an embryoid possessing a complete dorsal structure (a) Schematic drawing of dorsal marginal zone explant at ACE. (b) The explant of dorsal marginal zone at ACE. (c, d) The tailbud embryos developed from control and operated explant. Scale bars, 1 mm. (e-x) in situ hybridization of control and operated explant. Scale bars, 500 μm. The expression of bf1 (e, f), otx2 (g, h), rx2a (i, j), pax6 (k, l), krox20 (m, n), hairy2 (o, p), gsc (q, r), chd (s, t) in neurula stage. The expression of myoD (u, v), bra (w, x) in tailbud stage.

Ariizumi, Dose and time-dependent mesoderm induction and outgrowth formation by activin A in Xenopus laevis. 1991, Pubmed, Xenbase

Ariizumi, Dose and time-dependent mesoderm induction and outgrowth formation by activin A in Xenopus laevis. 1991, Pubmed , Xenbase
Asashima, Mesodermal induction in early amphibian embryos by activin A (erythroid differentiation factor). 1990, Pubmed , Xenbase
Cho, Molecular nature of Spemann's organizer: the role of the Xenopus homeobox gene goosecoid. 1991, Pubmed , Xenbase
Clevers, Wnt/β-catenin signaling and disease. 2012, Pubmed
Connolly, Chick noggin is expressed in the organizer and neural plate during axial development, but offers no evidence of involvement in primary axis formation. 1997, Pubmed , Xenbase
Danilchik, Differentiation of the animal-vegetal axis in Xenopus laevis oocytes. I. Polarized intracellular translocation of platelets establishes the yolk gradient. 1987, Pubmed , Xenbase
Gerhart, Cortical rotation of the Xenopus egg: consequences for the anteroposterior pattern of embryonic dorsal development. 1989, Pubmed , Xenbase
Hemmati-Brivanlou, Localization of specific mRNAs in Xenopus embryos by whole-mount in situ hybridization. 1990, Pubmed , Xenbase
Izpisúa-Belmonte, The homeobox gene goosecoid and the origin of organizer cells in the early chick blastoderm. 1993, Pubmed , Xenbase
Jorgensen, The mechanism and pattern of yolk consumption provide insight into embryonic nutrition in Xenopus. 2009, Pubmed , Xenbase
Keller, Time-lapse cinemicrographic analysis of superficial cell behavior during and prior to gastrulation in Xenopus laevis. 1978, Pubmed , Xenbase
Keller, Regional expression, pattern and timing of convergence and extension during gastrulation of Xenopus laevis. 1988, Pubmed , Xenbase
Kengaku, Basic fibroblast growth factor induces differentiation of neural tube and neural crest lineages of cultured ectoderm cells from Xenopus gastrula. 1993, Pubmed , Xenbase
Koide, When does the anterior endomesderm meet the anterior-most neuroectoderm during Xenopus gastrulation? 2002, Pubmed , Xenbase
Kozmikova, Wnt/β-catenin signaling is an evolutionarily conserved determinant of chordate dorsal organizer. 2020, Pubmed
Kuroda, Neural induction in Xenopus: requirement for ectodermal and endomesodermal signals via Chordin, Noggin, beta-Catenin, and Cerberus. 2004, Pubmed , Xenbase
Leikola, Hensen's node - the 'organizer' of the amniote embryo. 1976, Pubmed
Li, A single morphogenetic field gives rise to two retina primordia under the influence of the prechordal plate. 1997, Pubmed , Xenbase
McKendry, LEF-1/TCF proteins mediate wnt-inducible transcription from the Xenopus nodal-related 3 promoter. 1997, Pubmed , Xenbase
Nicolet, Avian gastrulation. 1971, Pubmed
Sakai, The vegetal determinants required for the Spemann organizer move equatorially during the first cell cycle. 1996, Pubmed , Xenbase
Sasai, Xenopus chordin: a novel dorsalizing factor activated by organizer-specific homeobox genes. 1994, Pubmed , Xenbase
Schohl, Beta-catenin, MAPK and Smad signaling during early Xenopus development. 2002, Pubmed , Xenbase
Smith, Expression cloning of noggin, a new dorsalizing factor localized to the Spemann organizer in Xenopus embryos. 1992, Pubmed , Xenbase
Takahashi, Two novel nodal-related genes initiate early inductive events in Xenopus Nieuwkoop center. 2000, Pubmed , Xenbase
Tejeda-Muñoz, Lysosomes are required for early dorsal signaling in the Xenopus embryo. 2022, Pubmed , Xenbase
Wakely, The chick embryo late primitive streak and head process studied by scanning electron microscopy. 1979, Pubmed
Weaver, GBP binds kinesin light chain and translocates during cortical rotation in Xenopus eggs. 2003, Pubmed , Xenbase
Winklbauer, Vegetal rotation, a new gastrulation movement involved in the internalization of the mesoderm and endoderm in Xenopus. 1999, Pubmed , Xenbase
Xie, Development of the hypothalamus: conservation, modification and innovation. 2017, Pubmed
Yamaguti, Xenopus hairy2b specifies anterior prechordal mesoderm identity within Spemann's organizer. 2005, Pubmed , Xenbase
Yan, Maternal Huluwa dictates the embryonic body axis through β-catenin in vertebrates. 2018, Pubmed , Xenbase
Yanagi, The Spemann organizer meets the anterior-most neuroectoderm at the equator of early gastrulae in amphibian species. 2015, Pubmed
Yu, Axial patterning in cephalochordates and the evolution of the organizer. 2007, Pubmed
Zhang, Topographic changes in nascent and early mesoderm in amphioxus embryos studied by DiI labeling and by in situ hybridization for a Brachyury gene. 1997, Pubmed