embryonic organizers

Summary

Summary: Cells in certain regions of an embryo that self-regulate embryonic development. These organizers have been found in dorsal and ventral poles of GASTRULA embryos, including Spemann organizer in amphibians, and Hensen node in chicken and mouse. These organizer cells communicate with each other via a network of secreted signaling proteins, such as BONE MORPHOGENETIC PROTEINS and their antagonists (chordin and noggin).

Top Publications

  1. Harland R. Neural induction. Curr Opin Genet Dev. 2000;10:357-62 pubmed
    ..Recent work has employed zebrafish, chick and mouse in addition to amphibians as models. Genetics has supplemented experimental embryology in enriching the understanding of the mechanism of neural induction and in posing new questions...
  2. Hidalgo Sanchez M, Millet S, Bloch Gallego E, Alvarado Mallart R. Specification of the meso-isthmo-cerebellar region: the Otx2/Gbx2 boundary. Brain Res Brain Res Rev. 2005;49:134-49 pubmed
    ..Otx2 and Gbx2 co-regulation could determine the precise location of the MH boundary and involved in the inductive events characteristic of the isthmic organizer center...
  3. Vincent S, Dunn N, Hayashi S, Norris D, Robertson E. Cell fate decisions within the mouse organizer are governed by graded Nodal signals. Genes Dev. 2003;17:1646-62 pubmed
    ..These findings conclusively demonstrate that graded Nodal/Smad2 signals govern allocation of the axial mesendoderm precursors that selectively give rise to the ADE and PCP mesoderm...
  4. Solnica Krezel L, Driever W. The role of the homeodomain protein Bozozok in zebrafish axis formation. Int J Dev Biol. 2001;45:299-310 pubmed
    ..Notably, Bozozok appears to function by repressing transcription of target genes such as swr (bmp2b) gene, and as such is the earliest acting repressor that the nascent dorsal axis is using to antagonize ventral influences...
  5. Bachiller D, Klingensmith J, Kemp C, Belo J, Anderson R, May S, et al. The organizer factors Chordin and Noggin are required for mouse forebrain development. Nature. 2000;403:658-61 pubmed
    ..The results show that BMP antagonists in the node and its derivatives are required for head development...
  6. Niehrs C. Regionally specific induction by the Spemann-Mangold organizer. Nat Rev Genet. 2004;5:425-34 pubmed
  7. Gilbert S. Continuity and change: paradigm shifts in neural induction. Int J Dev Biol. 2001;45:155-64 pubmed
  8. Bouchard M, Grote D, Craven S, Sun Q, Steinlein P, Busslinger M. Identification of Pax2-regulated genes by expression profiling of the mid-hindbrain organizer region. Development. 2005;132:2633-43 pubmed
    ..Together, these data defined novel functions of Pax2 in the establishment of distinct transcriptional programs and in the control of intracellular signaling during mid-hindbrain development...
  9. Kinder S, Tsang T, Wakamiya M, Sasaki H, Behringer R, Nagy A, et al. The organizer of the mouse gastrula is composed of a dynamic population of progenitor cells for the axial mesoderm. Development. 2001;128:3623-34 pubmed
    ..The gastrula organizer is therefore composed of a constantly changing population of cells that are allocated to different parts of the axial mesoderm...

More Information

Publications97

  1. Leung T, Bischof J, Söll I, Niessing D, Zhang D, Ma J, et al. bozozok directly represses bmp2b transcription and mediates the earliest dorsoventral asymmetry of bmp2b expression in zebrafish. Development. 2003;130:3639-49 pubmed
    ..Thus, similar to Drosophila Dpp, asymmetry of Bmp expression in zebrafish is initiated at the transcriptional level, and the shape of the gradient and its function as a morphogen are later modulated by post-transcriptional mechanisms...
  2. Wessely O, Agius E, Oelgeschlager M, Pera E, De Robertis E. Neural induction in the absence of mesoderm: beta-catenin-dependent expression of secreted BMP antagonists at the blastula stage in Xenopus. Dev Biol. 2001;234:161-73 pubmed
    ..The present results suggest an additional function for beta-Catenin, the early activation of expression of secreted BMP antagonists, such as Chordin, in a preorganizer region in the dorsal side of the Xenopus blastula...
  3. Wurst W, Bally Cuif L. Neural plate patterning: upstream and downstream of the isthmic organizer. Nat Rev Neurosci. 2001;2:99-108 pubmed
    ..Here we review our current knowledge on the identity, localization and maintenance of the isthmic organizer, as well as on the molecular cascades that underlie the activity of this organizing centre...
  4. Joyner A, Liu A, Millet S. Otx2, Gbx2 and Fgf8 interact to position and maintain a mid-hindbrain organizer. Curr Opin Cell Biol. 2000;12:736-41 pubmed
    ..Recent experiments have shown that Otx2, Gbx2 and Fgf8 genes play a major role in the positioning and functioning of this organizing center...
  5. Raible F, Brand M. Divide et Impera--the midbrain-hindbrain boundary and its organizer. Trends Neurosci. 2004;27:727-34 pubmed
    ..This article reviews recent progress in understanding the genetic and molecular components of the MHO, and how they synergize to control brain development...
  6. Sawada A, Nishizaki Y, Sato H, Yada Y, Nakayama R, Yamamoto S, et al. Tead proteins activate the Foxa2 enhancer in the node in cooperation with a second factor. Development. 2005;132:4719-29 pubmed
    ..These results suggest that Tead activates the Foxa2 enhancer core element in the mouse node in cooperation with a second factor that binds to the 5' element, and that a similar mechanism also operates in the zebrafish shield...
  7. Agius E, Oelgeschlager M, Wessely O, Kemp C, De Robertis E. Endodermal Nodal-related signals and mesoderm induction in Xenopus. Development. 2000;127:1173-83 pubmed
    ..The data support a modified model for mesoderm induction in Xenopus, in which mesoderm induction is mediated by a gradient of multiple Nodal-related signals released by endoderm at the blastula stage...
  8. Klingensmith J, Ang S, Bachiller D, Rossant J. Neural induction and patterning in the mouse in the absence of the node and its derivatives. Dev Biol. 1999;216:535-49 pubmed
    ..Our results indicate that the mammalian organizer is capable of neural induction and patterning of the neural plate, but that maintenance of an organizer-like signaling center is not necessary for either process...
  9. Tam P, Steiner K. Anterior patterning by synergistic activity of the early gastrula organizer and the anterior germ layer tissues of the mouse embryo. Development. 1999;126:5171-9 pubmed
    ..The formation of anterior neural structures therefore requires the synergistic interaction of the early gastrula organizer and anterior germ layer tissues...
  10. Kawahara A, Wilm T, Solnica Krezel L, Dawid I. Functional interaction of vega2 and goosecoid homeobox genes in zebrafish. Genesis. 2000;28:58-67 pubmed
    ..We suggest that vega2, in cooperation with vega1, functions as a negative regulator of organizer genes including gsc, and participates in the refinement of the gastrula organizer domain...
  11. Robb L, Tam P. Gastrula organiser and embryonic patterning in the mouse. Semin Cell Dev Biol. 2004;15:543-54 pubmed
    ..Recent findings show that the organiser activity is augmented by morphogenetic activity of the extraembryonic and embryonic endoderm, suggesting embryonic patterning is not solely the function of the organiser...
  12. Jin O, Harpal K, Ang S, Rossant J. Otx2 and HNF3beta genetically interact in anterior patterning. Int J Dev Biol. 2001;45:357-65 pubmed
    ..In addition, the forebrain truncations suggest an involvement of both genes in anterior patterning, through their overlapping expression domains in either the AVE and/or the prechordal mesoderm...
  13. Oelgeschlager M, Kuroda H, Reversade B, De Robertis E. Chordin is required for the Spemann organizer transplantation phenomenon in Xenopus embryos. Dev Cell. 2003;4:219-30 pubmed
    ..Unexpectedly, transplantations into the dorsal side revealed a cell-autonomous requirement of Chordin for neural plate differentiation...
  14. Lupo G, Harris W, Barsacchi G, Vignali R. Induction and patterning of the telencephalon in Xenopus laevis. Development. 2002;129:5421-36 pubmed
    ..Therefore, integration of organizer secreted molecules and of FGF, may account for patterning of the more rostral part of Xenopus CNS. ..
  15. Kumano G, Smith W. Revisions to the Xenopus gastrula fate map: implications for mesoderm induction and patterning. Dev Dyn. 2002;225:409-21 pubmed
    ..We present a model of mesoderm induction and patterning that integrates the new data on Spemann organizer-independent animal/vegetal patterning with data on other inductive pathways known to act on the gastrula marginal zone. ..
  16. Fauny J, Thisse B, Thisse C. The entire zebrafish blastula-gastrula margin acts as an organizer dependent on the ratio of Nodal to BMP activity. Development. 2009;136:3811-9 pubmed publisher
  17. Hiratani I, Mochizuki T, Tochimoto N, Taira M. Functional domains of the LIM homeodomain protein Xlim-1 involved in negative regulation, transactivation, and axis formation in Xenopus embryos. Dev Biol. 2001;229:456-67 pubmed
  18. Ariizumi T, Asashima M. In vitro induction systems for analyses of amphibian organogenesis and body patterning. Int J Dev Biol. 2001;45:273-9 pubmed
    ..The potential use of in vitro induction systems to further our understanding of vertebrate organogenesis and body patterning will be discussed. ..
  19. Enkhmandakh B, Makeyev A, Bayarsaihan D. The role of the proline-rich domain of Ssdp1 in the modular architecture of the vertebrate head organizer. Proc Natl Acad Sci U S A. 2006;103:11631-6 pubmed
  20. Cavodeassi F, Diez Del Corral R, Campuzano S, Dominguez M. Compartments and organising boundaries in the Drosophila eye: the role of the homeodomain Iroquois proteins. Development. 1999;126:4933-42 pubmed
  21. Lyman Gingerich J, Westfall T, Slusarski D, Pelegri F. hecate, a zebrafish maternal effect gene, affects dorsal organizer induction and intracellular calcium transient frequency. Dev Biol. 2005;286:427-39 pubmed
  22. Yelin R, Kot H, Yelin D, Fainsod A. Early molecular effects of ethanol during vertebrate embryogenesis. Differentiation. 2007;75:393-403 pubmed
    ..Our results provide evidence for the early molecular changes induced by EtOH exposure during embryogenesis, and may explain some of the structural changes that are part of the EtOH teratogenic phenotype also in FASD individuals. ..
  23. Meinhardt H. Models for organizer and notochord formation. C R Acad Sci III. 2000;323:23-30 pubmed
    ..Long extended structures can be formed as a trace behind the moving organizer. The notochord and the tracheae of insects are discussed as examples. ..
  24. Kelly C, Chin A, Leatherman J, Kozlowski D, Weinberg E. Maternally controlled (beta)-catenin-mediated signaling is required for organizer formation in the zebrafish. Development. 2000;127:3899-911 pubmed
    ..This work demonstrates that a maternal gene controlling localization of (beta)-catenin in dorsal nuclei is necessary for dorsal yolk syncytial layer gene activity and formation of the organizer in the zebrafish. ..
  25. Prothmann C, Armstrong N, Rupp R. The Toll/IL-1 receptor binding protein MyD88 is required for Xenopus axis formation. Mech Dev. 2000;97:85-92 pubmed
    ..We conclude that XMyD88 activity is required for normal Spemann organizer formation, implying an essential role for maternal Toll/IL-1 receptors in Xenopus axis formation. ..
  26. Shibata M, Itoh M, Ohmori S, Shinga J, Taira M. Systematic screening and expression analysis of the head organizer genes in Xenopus embryos. Dev Biol. 2001;239:241-56 pubmed
    ..These results indicate that our screening strategy is effective in isolating novel region-specific genes. ..
  27. Pera E, Kim J, Martinez S, Brechner M, Li S, Wessely O, et al. Isthmin is a novel secreted protein expressed as part of the Fgf-8 synexpression group in the Xenopus midbrain-hindbrain organizer. Mech Dev. 2002;116:169-72 pubmed
    ..Interestingly, xIsm was co-expressed with Fibroblast growth factor-8 (xFgf-8) at multiple sites including the MHB, indicating that these two genes are part of a synexpression group which also includes sprouty and sef homologs. ..
  28. Perea Gomez A, Rhinn M, Ang S. Role of the anterior visceral endoderm in restricting posterior signals in the mouse embryo. Int J Dev Biol. 2001;45:311-20 pubmed
    ..We propose that a genetic cascade in the AVE, involving HNF3beta, Lim1, Otx2, Smad2 and ActRIB, leads to the production of secreted TGFbeta antagonists that protect the anterior epiblast region from Nodal signalling. ..
  29. Varga M, Maegawa S, Bellipanni G, Weinberg E. Chordin expression, mediated by Nodal and FGF signaling, is restricted by redundant function of two beta-catenins in the zebrafish embryo. Mech Dev. 2007;124:775-91 pubmed
  30. Munoz Sanjuan I, Brivanlou A. Neural induction, the default model and embryonic stem cells. Nat Rev Neurosci. 2002;3:271-80 pubmed
  31. Echevarria D, Belo J, Martinez S. Modulation of Fgf8 activity during vertebrate brain development. Brain Res Brain Res Rev. 2005;49:150-7 pubmed
  32. Matsushita S, Urase K, Komatsu A, Scotting P, Kuroiwa A, Yasugi S. Foregut endoderm is specified early in avian development through signal(s) emanating from Hensen's node or its derivatives. Mech Dev. 2008;125:377-95 pubmed publisher
  33. Martinez S. The isthmic organizer and brain regionalization. Int J Dev Biol. 2001;45:367-71 pubmed
    ..Fgf8 appears as the active diffusible molecule for isthmic morphogenetic activity and has been suggested to be the morphogenetic effector in other inductive activities revealed in other neuroepithelial regions. ..
  34. Yamaguti M, Cho K, Hashimoto C. Xenopus hairy2b specifies anterior prechordal mesoderm identity within Spemann's organizer. Dev Dyn. 2005;234:102-13 pubmed
    ..These results suggest that Xhairy2b establishes the identity of the anterior prechordal mesoderm within Spemann's organizer by inhibiting the formation of neighboring tissues. ..
  35. Feistel K, Blum M. Three types of cilia including a novel 9+4 axoneme on the notochordal plate of the rabbit embryo. Dev Dyn. 2006;235:3348-58 pubmed
    ..Our data suggest that despite a highly conserved ciliogenic program, which initiates in the organizer, axonemal structures may vary widely within the vertebrates. ..
  36. Kramer Zucker A, Olale F, Haycraft C, Yoder B, Schier A, Drummond I. Cilia-driven fluid flow in the zebrafish pronephros, brain and Kupffer's vesicle is required for normal organogenesis. Development. 2005;132:1907-21 pubmed
    ..In Kupffer's vesicle, loss of flow is associated with loss of left-right patterning, indicating that the 'nodal flow' mechanism of generating situs is conserved in non-mammalian vertebrates. ..
  37. Ahn K, Mishina Y, Hanks M, Behringer R, Crenshaw E. BMPR-IA signaling is required for the formation of the apical ectodermal ridge and dorsal-ventral patterning of the limb. Development. 2001;128:4449-61 pubmed
    ..This study demonstrates that BMPR-IA signaling plays a crucial role in AER formation and in the establishment of the dorsal/ventral patterning during limb development. ..
  38. Delaloy C, Gao F. microRNA-9 multitasking near organizing centers. Nat Neurosci. 2008;11:625-6 pubmed publisher
  39. Tamplin O, Kinzel D, Cox B, Bell C, Rossant J, Lickert H. Microarray analysis of Foxa2 mutant mouse embryos reveals novel gene expression and inductive roles for the gastrula organizer and its derivatives. BMC Genomics. 2008;9:511 pubmed publisher
    ..However, the targets of Foxa2 during embryogenesis, and the molecular impact of organizer loss on the gastrula embryo, have not been well defined...
  40. Fletcher R, Harland R. The role of FGF signaling in the establishment and maintenance of mesodermal gene expression in Xenopus. Dev Dyn. 2008;237:1243-54 pubmed publisher
    ..Inhibition of FGF signaling prevents VegT activation of specific mesodermal transcripts. These findings illuminate how FGF signaling contributes to the establishment of distinct types of mesoderm. ..
  41. Chung A, Xu X, Niederreither K, Cooney A. Loss of orphan nuclear receptor GCNF function disrupts forebrain development and the establishment of the isthmic organizer. Dev Biol. 2006;293:13-24 pubmed
    ..Increased cell death may contribute to the loss of midbrain structure in GCNF-/- embryos. These results indicate that GCNF is required for establishment of the isthmic organizer, thereby regulating the midbrain development. ..
  42. Horder T. The organizer concept and modern embryology: Anglo-American perspectives. Int J Dev Biol. 2001;45:97-132 pubmed
    ..It is argued that historical considerations need to be included as part of the use and critical assessment of basic concepts in science. ..
  43. Passamaneck Y, Di Gregorio A. Ciona intestinalis: chordate development made simple. Dev Dyn. 2005;233:1-19 pubmed
    ..Here, we review the main similarities and differences so far identified, at the molecular level, between ascidian and vertebrate tissues and discuss the evolution of the compact ascidian genome...
  44. Ro H, Dawid I. Organizer restriction through modulation of Bozozok stability by the E3 ubiquitin ligase Lnx-like. Nat Cell Biol. 2009;11:1121-7 pubmed publisher
    ..These studies introduce a ubiquitin ligase, Lnx-l, as a balancing modulator of axial patterning in the zebrafish embryo. ..
  45. Maderspacher F. Original organisers. Curr Biol. 2007;17:R863-4 pubmed
  46. Kourakis M, Smith W. Did the first chordates organize without the organizer?. Trends Genet. 2005;21:506-10 pubmed
  47. Gerhart J. Evolution of the organizer and the chordate body plan. Int J Dev Biol. 2001;45:133-53 pubmed
    ..This addition to the organizer is seen as a major event in chordate evolution, bringing body organization beyond that achieved by oocyte organization and meso-endoderm induction in other groups. ..
  48. Niehrs C. Developmental biology: a tale of tails. Nature. 2003;424:375-6 pubmed
  49. Borgave S, Ghaskadbi S. Modulation of cell surface architecture in gastrulating chick embryo in response to altered fibroblast growth factor (FGF) signaling. Indian J Exp Biol. 2010;48:346-53 pubmed
    ..Further, the dynamic nature of these cell surface features by their response to altered fibroblast growth factor (FGF) signaling, experimentally created by using either excess FGF or inhibition of FGF signaling are demonstrated...
  50. Bajpai R, Sambrani N, Stadelmayer B, Shashidhara L. Identification of a novel target of D/V signaling in Drosophila wing disc: Wg-independent function of the organizer. Gene Expr Patterns. 2004;5:113-21 pubmed
    ..The non-cell autonomous nature of Ubx-mediated repression of CG32062 expression suggests that the novel component of D/V signaling is also negatively regulated during haltere specification...
  51. Long S, Ahmad N, Rebagliati M. The zebrafish nodal-related gene southpaw is required for visceral and diencephalic left-right asymmetry. Development. 2003;130:2303-16 pubmed
    ..These observations lead to a model of how visceral organ and brain left-right asymmetry are coordinated during embryogenesis...
  52. Mayor R, Guerrero N, Young R, Gomez Skarmeta J, Cuellar C. A novel function for the Xslug gene: control of dorsal mesendoderm development by repressing BMP-4. Mech Dev. 2000;97:47-56 pubmed
    ..Our results indicate that this effect on mesodermal patterning depends on BMP activity, showing that Xslug can directly control the transcription of BMP-4...
  53. Liu J, Laufer E, Jessell T. Assigning the positional identity of spinal motor neurons: rostrocaudal patterning of Hox-c expression by FGFs, Gdf11, and retinoids. Neuron. 2001;32:997-1012 pubmed
  54. Eakin G, Behringer R. Diversity of germ layer and axis formation among mammals. Semin Cell Dev Biol. 2004;15:619-29 pubmed
    ..We suggest that more studies of embryonic development in diverse mammalian species are required for an understanding of germ layer and axis formation to provide insights into human biology and disease...
  55. Schlange T, Schnipkoweit I, Andree B, Ebert A, Zile M, Arnold H, et al. Chick CFC controls Lefty1 expression in the embryonic midline and nodal expression in the lateral plate. Dev Biol. 2001;234:376-89 pubmed
    ..Thus, chick CFC seems to have a dual function in left-right axis formation by maintaining Nodal expression in the lateral plate mesoderm and controlling expression of Lefty1 expression in the midline territory...
  56. De Robertis E. Spemann's organizer and the self-regulation of embryonic fields. Mech Dev. 2009;126:925-41 pubmed publisher
    ..This remarkable dorsal-ventral positional information network has been conserved in evolution and is ancestral to all bilateral animals...
  57. Dathe V, Gamel A, Männer J, Brand Saberi B, Christ B. Morphological left-right asymmetry of Hensen's node precedes the asymmetric expression of Shh and Fgf8 in the chick embryo. Anat Embryol (Berl). 2002;205:343-54 pubmed
  58. Bouwmeester T. The Spemann-Mangold organizer: the control of fate specification and morphogenetic rearrangements during gastrulation in Xenopus. Int J Dev Biol. 2001;45:251-8 pubmed
  59. Li N, Volff J, Wizenmann A. Rab23 GTPase is expressed asymmetrically in Hensen's node and plays a role in the dorsoventral patterning of the chick neural tube. Dev Dyn. 2007;236:2993-3006 pubmed
    ..These data indicate that Rab23 plays an important role in patterning the dorso-ventral axis by dorsalizing the neural tube...
  60. Joshi Banka D, Paranjape S, Ghaskadbi S, Modak S. Post-nodal mesoblast caudalizes the host axis and inhibits cell population growth, and induces new primitive streaks in chick embryos. Dev Growth Differ. 2002;44:169-80 pubmed
    ..When placed near the host axis, PN caudalized it and inhibited cell population growth...
  61. Garcia Fernandez J, D Aniello S, Escriva H. Organizing chordates with an organizer. Bioessays. 2007;29:619-24 pubmed
    ..The organizer was then lost in the urochordate lineage, most probably as an adaptation to a rapid and determinate development...
  62. McGrath J, Somlo S, Makova S, Tian X, Brueckner M. Two populations of node monocilia initiate left-right asymmetry in the mouse. Cell. 2003;114:61-73 pubmed
  63. Charrier J, Teillet M, Lapointe F, Le Douarin N. Defining subregions of Hensen's node essential for caudalward movement, midline development and cell survival. Development. 1999;126:4771-83 pubmed
    ..Hensen's node-derived structures (notochord and floor plate) thus appear to produce maintenance factor(s) that ensures the survival and further development of adjacent tissues...
  64. Slusarski D, Pelegri F. Calcium signaling in vertebrate embryonic patterning and morphogenesis. Dev Biol. 2007;307:1-13 pubmed
    ..Finally, we summarize recent evidence that propose a role for calcium signaling in stem cell biology and human developmental disorders...
  65. Steiner A, Engleka M, Lu Q, Piwarzyk E, Yaklichkin S, Lefebvre J, et al. FoxD3 regulation of Nodal in the Spemann organizer is essential for Xenopus dorsal mesoderm development. Development. 2006;133:4827-38 pubmed
    ..Therefore, FoxD3 is required for Nodal expression in the Spemann organizer and this function is essential for dorsal mesoderm formation...
  66. Basler K. EMBO Gold Medal 1999. Waiting periods, instructive signals and positional information. EMBO J. 2000;19:1168-75 pubmed
  67. Belting H, Hauptmann G, Meyer D, Abdelilah Seyfried S, Chitnis A, Eschbach C, et al. spiel ohne grenzen/pou2 is required during establishment of the zebrafish midbrain-hindbrain boundary organizer. Development. 2001;128:4165-76 pubmed
    ..Thus, expression of pou2 does not depend on fgf8 and pax2.1. Our data suggest that pou2 is required for the establishment of the normal expression domains of wnt1 and pax2.1 in the MHB primordium...
  68. Yasuoka Y, Kobayashi M, Kurokawa D, Akasaka K, Saiga H, Taira M. Evolutionary origins of blastoporal expression and organizer activity of the vertebrate gastrula organizer gene lhx1 and its ancient metazoan paralog lhx3. Development. 2009;136:2005-14 pubmed publisher
  69. Bellipanni G, Varga M, Maegawa S, Imai Y, Kelly C, Myers A, et al. Essential and opposing roles of zebrafish beta-catenins in the formation of dorsal axial structures and neurectoderm. Development. 2006;133:1299-309 pubmed
    ..We propose that the early, dorsal-promoting function of beta-catenin-2 is essential to counteract a later, dorsal- and neurectoderm-repressing function that is shared by both beta-catenin genes...
  70. Ueno N. [Mesoderm induction and neural induction]. Tanpakushitsu Kakusan Koso. 2005;50:583-7 pubmed
  71. Crozatier M, Glise B, Vincent A. Connecting Hh, Dpp and EGF signalling in patterning of the Drosophila wing; the pivotal role of collier/knot in the AP organiser. Development. 2002;129:4261-9 pubmed
    ..A model recapitulating the molecular interplay between the Hh, Dpp and EGF signalling pathways in the wing AP organiser is presented...
  72. Houston D, Kofron M, Resnik E, Langland R, Destree O, Wylie C, et al. Repression of organizer genes in dorsal and ventral Xenopus cells mediated by maternal XTcf3. Development. 2002;129:4015-25 pubmed
    ..These data show that normal dorsal gene expression in the embryo requires the transcriptional activator VegT, whilst XTcf3 prevents their inappropriate expression on the ventral side of the embryo...
  73. Glavic A, Gomez Skarmeta J, Mayor R. Xiro-1 controls mesoderm patterning by repressing bmp-4 expression in the Spemann organizer. Dev Dyn. 2001;222:368-76 pubmed
    ..Thus, Xiro-1 seems to have at least two different functions: control of neural plate and organizer development, both of which could be mediated by repression of bmp-4 transcription...
  74. Streit A, Berliner A, Papanayotou C, Sirulnik A, Stern C. Initiation of neural induction by FGF signalling before gastrulation. Nature. 2000;406:74-8 pubmed
    ..We show that the organizer and some of its precursor cells produce a fibroblast growth factor signal, which can initiate, and is required for, neural induction...
  75. Wang S, Yu X, Zhang T, Zhang X, Zhang Z, Chen Y. Chick Pcl2 regulates the left-right asymmetry by repressing Shh expression in Hensen's node. Development. 2004;131:4381-91 pubmed
  76. Przemeck G, Heinzmann U, Beckers J, Hrabe de Angelis M. Node and midline defects are associated with left-right development in Delta1 mutant embryos. Development. 2003;130:3-13 pubmed
    ..Based on expression analysis in wild-type and mutant embryos, we suggest a model, in which Notch signalling is required for the proper differentiation of node cells and node morphology...
  77. Manner J. Does an equivalent of the "ventral node" exist in chick embryos? A scanning electron microscopic study. Anat Embryol (Berl). 2001;203:481-90 pubmed
    ..It is unlikely that nodal cilia are required for initiating the L-R patterning in chick embryos...
  78. Hwang Y, Seo J, Cha S, Lee H, Lee S, Roh D, et al. Antimorphic PV.1 causes secondary axis by inducing ectopic organizer. Biochem Biophys Res Commun. 2002;292:1081-6 pubmed
    ..1 functions at downstream of BMP-4 as a ventralizing effector which acts separately from Xvent-2 and the dominant negative effect gained by this specific mutant is applicable for the further studies of BMP-4 downstream pathway...
  79. Leucht C, Stigloher C, Wizenmann A, Klafke R, Folchert A, Bally Cuif L. MicroRNA-9 directs late organizer activity of the midbrain-hindbrain boundary. Nat Neurosci. 2008;11:641-8 pubmed publisher
    ..Together, these findings highlight a previously unknown mechanism by which a single microRNA fine-tunes late MHB coherence via its co-regulation of patterning activities and neurogenesis...
  80. Gerhart J. Enzymes, embryos, and ancestors. Annu Rev Cell Dev Biol. 2010;26:1-20 pubmed publisher
    ..I've thoroughly enjoyed exploring these areas during a 50-year period of great advances in biological sciences by the worldwide research community...
  81. Skoglund P, Dzamba B, Coffman C, Harris W, Keller R. Xenopus fibrillin is expressed in the organizer and is the earliest component of matrix at the developing notochord-somite boundary. Dev Dyn. 2006;235:1974-83 pubmed
    ..This pattern of protein deposition combines to give the appearance of an "embryonic skeleton," suggesting that one role for XF is to serve as a mechanical element in the embryo prior to bone deposition...
  82. Murato Y, Yamaguti M, Katamura M, Cho K, Hashimoto C. Two modes of action by which Xenopus hairy2b establishes tissue demarcation in the Spemann-Mangold organizer. Int J Dev Biol. 2006;50:463-71 pubmed
    ..Our study provides new insight into how a region of the vertebrate embryo is demarcated by one dual-functional transcription factor in the early stages of development...
  83. Branford W, Yost H. Lefty-dependent inhibition of Nodal- and Wnt-responsive organizer gene expression is essential for normal gastrulation. Curr Biol. 2002;12:2136-41 pubmed
    ..We hypothesize that Xlefty negatively regulates the spatial extent of Nodal- and Wnt-responsive gene expression in the organizer and that this Xlefty-dependent inhibition is essential for normal organizer patterning and gastrulation...
  84. Dehal P, Satou Y, Campbell R, Chapman J, Degnan B, De Tomaso A, et al. The draft genome of Ciona intestinalis: insights into chordate and vertebrate origins. Science. 2002;298:2157-67 pubmed
    ..The ascidian genome has also acquired a number of lineage-specific innovations, including a group of genes engaged in cellulose metabolism that are related to those in bacteria and fungi...
  85. Karabagli H, Karabagli P, Ladher R, Schoenwolf G. Comparison of the expression patterns of several fibroblast growth factors during chick gastrulation and neurulation. Anat Embryol (Berl). 2002;205:365-70 pubmed
    ..As well as providing a comparison of the expression patterns of those fibroblast growth factors already published, we provide new data on the expression patterns of some of these genes at early stages...
  86. Mitchell T, Sheets M. The FGFR pathway is required for the trunk-inducing functions of Spemann's organizer. Dev Biol. 2001;237:295-305 pubmed
    ..The implications of our findings for the evolutionarily conserved role of the FGFR pathway in the functions of Spemann's organizer and other vertebrate-signaling centers are discussed...
  87. Cavodeassi F, Modolell J, Gomez Skarmeta J. The Iroquois family of genes: from body building to neural patterning. Development. 2001;128:2847-55 pubmed
    ..Later in development in both Drosophila and vertebrates, the Iro genes function again to subdivide those territories into smaller domains...
  88. Patil S, Alexander T, Uzman J, Lou C, Gohil H, Sater A. Novel gene ashwin functions in Xenopus cell survival and anteroposterior patterning. Dev Dyn. 2006;235:1895-907 pubmed
    ..Orthologues have been identified in the human, mouse, chicken, and pufferfish genomes. Our results suggest that ashwin regulates cell survival and anteroposterior patterning...