The zebrafish locus one-eyed pinhead (oep) is essential for the formation of anterior axial mesoderm, endoderm and ventral neuroectoderm. At the beginning of gastrulation anterior axial mesoderm cells form the prechordal plate and express goosecoid (gsc) in wild-type embryos. In oep mutants the prechordal plate does not form and gsc expression is not maintained. Exposure to lithium, a dorsalizing agent, leads to the ectopic induction and maintenance of gsc expression in wild-type embryos. Lithium treatment of oep mutants still leads to ectopic gsc induction but not maintenance, suggesting that oep acts downstream of inducers of dorsal mesoderm. In genetic mosaics, wild-type cells are capable of forming anterior axial mesoderm in oep embryos, suggesting that oep is required in prospective anterior axial mesoderm cells before gastrulation. The oep gene is also essential for endoderm formation and the early development of ventral neuroectoderm, including the floor plate. The loss of endoderm is already manifest during gastrulation by the absence of axial-expressing cells in the hypoblast of oep mutants. These findings suggest that oep is also required in lateral and ventral regions of the gastrula margin. The sonic hedgehog (shh).gene is expressed in the notochord of oep animals. Therefore, the impaired floor plate development in oep mutants is not caused by the absence of the floor plate inducer shh. This suggests that oep is required downstream or in parallel to shh signaling. The ventral region of the forebrain is also absent in oep mutants, leading to severe cyclopia. In contrast, anterior-posterior brain patterning appears largely unaffected, suggesting that underlying prechordal plate is not required for anterior-posterior pattern formation but might be involved in dorsoventral brain patterning. To test if oep has a wider, partially redundant role, we constructed double mutants with two other zebrafish loci essential for patterning during gastrulation. Double mutants with floating head, the zebrafish Xnot homologue, display enhanced floor plate and adaxial muscle phenotypes. Double mutants with no tail (ntl), the zebrafish homologue of the mouse Brachyury locus, display severe defects in midline and mesoderm formation including absence of most of the somitic mesoderm. These results reveal a redundant function of oep and ntl in mesoderm formation. Our data suggest that both oep and ntl act in the blastoderm margin to specify mesendodermal cell fates.

Acampora
D.
,
Mazan
S.
,
Lallemand
Y.
,
Avantaggiato
V.
,
Maury
M.
,
Simeone
A.
,
Brulet
P.
(
1995
)
Forebrain and midbrain regions are deleted in Otx2/ mutants due to a defective anterior neuroectoderm specification during gastrulation.
Development
121
,
3279
90
Adelmann
H. B.
(
1932
)
The development of the prechordal plate and mesoderm of Amblystoma punctatum.
J. Morph
54
,
1
67
Adelmann
H. B.
(
1936
)
The problem of cyclopia.
Part II. Q. Rev. Biol
11
,
284
304
Ang
S.-L.
,
Jin
O.
,
Rhinn
M.
,
Daigle
N.
,
Stevenson
L.
,
Rossant
J.
(
1996
)
A targeted mouse otx2 mutation leads to severe defects in gastrulation and formation of axial mesoderm and to deletion of rostral brain.
Development
122
,
243
252
Ang
S. L.
,
Conlon
R. A.
,
Jin
O.
,
Rossant
J.
(
1994
)
Positive and negative signals from mesoderm regulate the expression of mouse Otx2 in ectoderm explants.
Development
120
,
2979
2989
Ang
S. L.
,
Rossant
J.
(
1993
)
Anterior mesendoderm induces mouse Engrailed genes in explant cultures.
Development
118
,
139
149
Ang
S. L.
,
Rossant
J.
(
1994
)
HNF-3 beta is essential for node and notochord formation in mouse development.
Cell
78
,
561
574
Ang
S. L.
,
Wierda
A.
,
Wong
D.
,
Stevens
K. A.
,
Cascio
S.
,
Rossant
J.
,
Zaret
K. S.
(
1993
)
The formation and maintenance of the definitive endoderm lineage in the mouse: involvement of HNF3/forkhead proteins.
Development
119
,
1301
1315
Asashima
M.
,
Uchiyama
H.
,
Nakano
H.
,
Eto
Y.
,
Ejima
D.
,
Sugino
H.
,
Davids
M.
,
Plessow
S.
,
Born
J.
,
Hoppe
P.
,
Tiedemann
H.
,
Tiedemann
N.
(
1991
)
The vegetalizing factor from chicken embryos: Its EDF (activin A)-like activity.
Mech. Dev
34
,
135
141
Barth
K. A.
,
Wilson
S.
(
1995
).
Expression of zebrafish nk2.2 is influenced by sonic hedgehog/vertebrate hedgehog-1 and demarcates a zone of neuronal differentiation in the embryonic forebrain.
Development
121
,
1755
1768
Blumberg
B.
,
Wright
C. V.
,
De Robertis
E. M.
,
Cho
K. W.
(
1991
)
Organizer-specific homeobox genes in Xenopus laevis embryos.
Science
253
,
194
196
Chesley
P.
(
1935
)
Development of the short-tailed mutation in the house mouse.
J. Exp. Zool
70
,
429
459
Cho
K. W. Y.
,
Blumberg
B.
,
Steinbeisser
H.
,
DeRobertis
E. M.
(
1991
)
Molecular nature of Spemann's organizer: the role of the Xenopus homeobox gene goosecoid.
Cell
67
,
1111
1120
Conlon
F. L.
,
Wright
C. V.
,
Robertson
E. J.
(
1995
)
Effects of the TWismutation on notochord formation and mesodermal patterning.
Mechanisms of Development
49
,
201
209
Cornell
R. A.
,
Musci
T. J.
,
Kimelman
D.
(
1995
)
FGF is a prospective competence factor for early activin-type signals in Xenopus mesoderm induction.
Development
121
,
2429
2437
Cunliffe
V.
,
Smith
J. C.
(
1992
)
Ectopic mesoderm formation in Xenopus embryos caused by widespread expression of a Brachyury homologue.
Nature
358
,
427
430
Cunliffe
V.
,
Smith
J. C.
(
1994
)
Specification of mesodermal pattern in Xenopus laevis by interactions between Brachyury, noggin and Xwnt-8.
EMBO
13
,
349
359
Detrich
H. W.
3rd.
,
Kieran
M. W.
,
Chan
F. Y.
,
Barone
L. M.
,
Yee
K.
,
Rundstadler
J. A.
,
Pratt
S.
,
Ransom
D.
,
Zon
L. I.
(
1995
)
Intraembryonic hematopoietic cell migration during vertebrate development.
Proc. Nat. Acad. Sci.USA
92
,
10713
10717
Dietrich
S.
,
Schubert
F. R.
,
Gruss
P.
(
1993
)
Altered Pax gene expression in murine notochord mutants: the notochord is required to initiate and maintain ventral identity in the somite.
Mech. Dev
44
,
189
207
Dirksen
M. L.
,
Jamrich
M.
(
1992
)
A novel, activin-inducible, blastopore lip-specific gene of Xenopus laevis contains a fork head DNA-binding domain.
Genes Dev
6
,
599
608
Dixon
J.
,
Kintner
C.
(
1989
)
Cellular contacts required for neural induction in Xenopus embryos: evidence for two signals.
Development
106
,
749
757
Doniach
T.
,
Phillips
C. R.
,
Gerhart
J. C.
(
1992
)
Planar induction of anteroposterior pattern in the developing central nervous system of Xenopus laevis.
Science
257
,
542
545
Doniach
T.
(
1995
)
Basic FGF as an inducer of anteroposterior neural pattern.
Cell
83
,
1067
1070
Driever
W.
,
Solnica-Krezel
L.
,
Schier
A. F.
,
Neuhauss
S. C. F.
,
Malicki
J.
,
Stemple
D. L.
,
Stainier
D. Y. R.
,
Zwartkruis
F.
,
Abdelilah
S.
,
Rangini
Z.
,
Mountcastle-Shah
E.
,
Harvey
M.
,
Belak
J.
,
Boggs
C.
(
1996
)
A genetic screen for mutations affecting embryogenesis in zebrafish.
Development
123
,
37
46
Echelard
Y.
,
Epstein
D. J.
,
St-Jacques
B.
,
Shen
L.
,
Mohler
J.
,
McMahon
J. A.
,
McMahon
A. P.
(
1993
)
Sonic hedgehog, a member of a family of putative signaling molecules, is implicated in the regulation of CNS polarity.
Cell
75
,
1417
1430
Fjose
A.
,
Izpisua-Belmonte
J. C.
,
Fromental-Ramain
C.
,
Duboule
D.
(
1994
)
Expression of the zebrafish gene hlx-1 in the prechordal plate and during CNS development.
Development
120
,
71
81
Gamer
L. W.
,
Wright
C. V.
(
1995
)
Autonomous endodermal determination in Xenopus: regulation of expression of the pancreatic gene XlHbox 8.
Dev. Biol
171
,
240
251
Gerhart
J.
,
Danilchik
M.
,
Doniach
T.
,
Roberts
S.
,
Rowning
B.
,
Stewart
R.
(
1989
)
Cortical rotation of the Xenopus egg: consequences for the anteroposterior pattern of embryonic dorsal development.
Development
107
,
37
51
Gluecksohn-Schoenheimer
S.
(
1944
)
The development of normal and homozygous Brachyury (T/T) mouse embryos in the extraembryonic coelom of the chick.
Proc. Nat. Acad. Sci. USA
30
,
134
140
Graveson
A. C.
,
Armstrong
J. B.
(
1987
)
Differentiation of cartilage from cranial neural crest in the axolotl (Amblystoma mexicanum).
Differentiation
35
,
16
20
Grueneberg
H. J.
(
1958
)
Genetic studies on the skeleton of the mouse. XXIII. The development of Brachyury and Anury.
J. Embryol. Exp. Morph
6
,
424
443
Halpern
M. E.
,
Ho
R. K.
,
Walker
C.
,
Kimmel
C. B.
(
1993
)
Induction of muscle pioneers and floor plate is distinguished by the zebrafish no tail mutation.
Cell
75
,
99
111
Halpern
M. E.
,
Thisse
C.
,
Ho
R. K.
,
Thisse
B.
,
Riggleman
B.
,
Trevarrow
B.
,
Weinberg
E. S.
,
Postlethwait
J. H.
,
Kimmel
C. B.
(
1995
)
Cell-autonomous shift from axial to paraxial mesodermal development in zebrafish floating head mutants.
Development
121
,
4257
4264
Hammerschmidt
M.
,
Nusslein-Volhard
C.
(
1993
)
The expression of a zebrafish gene homologous to Drosophila snail suggests a conserved function in invertebrate and vertebrate gastrulation.
Development
119
,
1107
1118
Hammerschmidt
M.
,
Pelegri
F.
,
Mullins
M.C.
,
Kane
D.A.
,
Brand
M.
,
van Eeden
F.J.M.
,
Furutani-Seiki
M.
,
Granato
M.
,
Haffter
P.
,
Heisenberg
C.-F.
,
Jiang
Y.-J.
,
Kelsh
R. N.
,
Odenthal
J.
,
Warga
R. M.
,
Nusslein-Volhard
C.
(
1996
)
Mutations affecting morphogenesis during gastrulation and tail formation in the zebrafish, Danio rerio.
Development,
123
,
95
102
Hatta
K.
,
Kimmel
C. B.
,
Ho
R. K.
,
Walker
C.
(
1991
)
The cyclops mutation blocks specification of the floor plate of the zebrafish central nervous system.
Nature
350
,
339
341
Hatta
K.
,
Puschel
A. W.
,
Kimmel
C. B.
(
1994
)
Midline signaling in the primordium of the zebrafish anterior central nervous system.
Proc. Nat. Acad. Sci. USA
91
,
2061
2065
Helde
K. A.
,
Wilson
E. T.
,
Cretekos
C. J.
,
Grunwald
D. J.
(
1994
)
Contribution of early cells to the fate map of the zebrafish gastrula.
Science
265
,
517
520
Henry
G. L.
,
Brivanlou
I. H.
,
Kessler
D. S.
,
Hemmati-Brivanlou
A.
,
Melton
D. A.
(
1996
)
TGF-beta signals and a prepattern in Xenopus laevis endodermal development.
Development
122
,
1007
1015
Herrman
B.
,
Labeit
S.
,
Poustka
A.
,
King
T. R.
,
Lehrach
H.
(
1990
)
Cloning of the T gene required in mesoderm formation in the mouse.
Nature
343
,
617
622
Herrmann
B. G.
,
Kispert
A.
(
1994
)
The T genes in embryogenesis.
Trends in Genetics
10
,
280
286
Ho
R. K.
,
Kane
D. A.
(
1990
)
Cell-autonomous action of zebrafish spt-1 mutation in specific mesodermal precursors.
Nature
348
,
728
730
Holley
S. A.
,
Jackson
P. D.
,
Sasai
Y.
,
Lu
B.
,
De Robertis
E. M.
,
Hoffmann
F. M.
,
Ferguson
E. L.
(
1995
)
A conserved system fordorsal-ventral patterning in insects and vertebrates involving sog and chordin.
Nature
376
,
249
253
Ingham
P. W.
(
1995
)
Signalling by hedgehog family proteins in Drosophila and vertebrate development.
Curr. Opin. Genet. Dev
5
,
492
498
Inohaya
K.
,
Yasumasu
S.
,
Ishimaru
M.
,
Ohyama
A.
,
Iuchi
I.
,
Yamagami
K.
(
1995
)
Temporal and spatial patterns of gene expression for the hatching enzyme in the teleost embryo, Oryzias latipes.
Dev. Biol
171
,
374
385
Inoue
A.
,
Takahashi
M.
,
Hatta
K.
,
Hotta
Y.
,
Okamoto
H.
(
1994
)
Developmental regulation of islet-1 mRNA expression during neuronal differentiation in embryonic zebrafish.
Dev. Dyn
199
,
1
11
Jacob
M.
,
Jacob
H. J.
,
Wachtler
F.
,
Christ
B.
(
1984
)
Onotogeny of avian extrinsic ocular muscles. I. A light-and electron-microscopic study.
Cell Tissue Res
237
,
549
557
Jacobson
A. G.
,
Duncan
J. T.
(
1968
)
Heart induction in salamanders.
J. Exp. Zool
167
,
79
103
Johnson
S. L.
,
Gates
M. A.
,
Johnson
M.
,
Talbot
W. S.
,
Horne
S.
,
Baik
K.
,
Rude
S.
,
Wong
J. R.
,
Postlethwait
J. H.
(
1996
)
Centromere-linkage analysis and consolidation of the zebrafish genetic map.
Genetics
142
,
1277
1288
Jowett
T.
,
Lettice
L.
(
1994
)
Whole-mount in situ hybridizations on zebrafish embryos using a mixture of digoxigenin-and fluorescein-labelled probes.
Trends Genetics
10
,
73
4
Keller
R. E.
(
1976
)
Vital dye mapping of the gastrula and neurula of Xenopus laevis. II. Prospective areas and morphogenetic movements of the deep layer.
Dev. Biol
51
,
118
137
Kessler
D. S.
,
Melton
D. A.
(
1994
)
Vertebrate embryonic induction: Mesodermal and neural patterning.
Science
266
,
596
604
Kimelman
D.
,
Christian
J. L.
,
Moon
R. T.
(
1992
)
Synergistic principles of development: overlapping patterning systems in Xenopus mesoderm induction. [Review].
Development
116
,
1
9
Kimmel
C. B.
,
Ballard
W. W.
,
Kimmel
S. R.
,
Ullmann
B.
,
Schilling
T. F.
(
1995
)
Stages of embryonic development of the zebrafish.
Dev. Dynam
203
,
253
310
Kimmel
C. B.
,
Warga
R. M.
,
Schilling
T. F.
(
1990
)
Origin and organization of the zebrafish fate map.
Development
108
,
581
94
Klar
A.
,
Baldassare
M.
,
Jessell
T. M.
(
1992
)
F-spondin: a gene expressed at high levels in the floor plate encodes a secreted protein that promotes neural cell adhesion and neurite extension.
Cell
69
,
95
110
Knapik
E. W.
,
Goodmann
A.
,
Atkinson
S.
,
Roberts
C. T.
,
Shiozawa
M.
,
Sim
C. U.
,
Weksler-Zangen
S.
,
Trolliet
M.
,
Futrell
C.
,
Innes
B. A.
,
Koike
G.
,
McLaughlin
M. G.
,
Pierre
L.
,
Simson
J. S.
,
Vilallonga
E.
,
Roy
M.
,
Chiang
P.
,
Fishman
M. C.
,
Driever
W.
,
Jacob
H. J.
(
1996
)
A reference cross DNA panel for zebrafish (Danio rerio) anchored with simple sequence length polymorphisms.
Development,
123
,
451
460
Knoechel
S.
,
Lef
J.
,
Clement
J.
,
Klocke
B.
,
Hille
S.
,
Koster
M.
,
Knoechel
W.
(
1992
)
Activin A induced expression of a fork head related gene in posterior chordamesoderm (notochord) of Xenopus laevis embryos.
Mech. Dev
38
,
157
165
Korzh
V.
,
Edlund
T.
,
Thor
S.
(
1993
)
Zebrafish primary neurons initiate expression of the LIM homeodomain protein Isl-1 at the end of gastrulation.
Development
118
,
417
425
Krauss
S.
,
Concordet
J. P.
,
Ingham
P. W.
(
1993
)
A functionally conserved homolog of the Drosophila segment polarity gene hh is expressed in tissues with polarizing activity in zebrafish embryos.
Cell
75
,
1431
1444
Krauss
S.
,
Johansen
T.
,
Korzh
V.
,
Moens
U.
,
Ericson
J. U.
,
Fjose
A.
(
1991
)
Zebrafish pax[zf-a]: a paired box-containing gene expressed in the neural tube.
EMBO Journal
10
,
3609
3619
Krauss
S.
,
Maden
M.
,
Holder
N.
,
Wilson
S. W.
(
1992
)
Zebrafish pax[b] is involved in the formation of the midbrain-hindbrain boundary.
Nature
360
,
87
89
Lamb
T. M.
,
Knecht
A. K.
,
Smith
W. C.
,
Stachel
S. E.
,
Economides
A. N.
,
Stahl
N.
,
Yancopolous
G. D.
,
Harland
R. M.
(
1993
)
Neural induction by the secreted polypeptide noggin.
Science
262
,
713
718
Mangold
O.
(
1933
)
Ueber die Induktionsfaehigkeit der verschiedenen Bezirke der Neurula von Urodelen.
Naturwissenschaften
21
,
761
766
Matsuo
I.
,
Kuratani
S.
,
Kimura
C.
,
Takeda
N.
,
Aizawa
S.
(
1995
)
Mouse Otx2 functions in the formation and patterning of rostral head.
Genes & Development
9
,
2646
2658
Monaghan
A. P.
,
Kaestner
K. H.
,
Grau
E.
,
Schutz
G.
(
1993
)
Postimplantation expression patterns indicate a role for the mouseforkhead/HNF-3alpha, beta and gamma genes in determination of the definitive endoderm, chordamesoderm and neuroectoderm.
Development
119
,
567
578
Moon
R. T.
(
1993
)
In pursuit of the functions of the Wnt family of Developmental Regulators-Insights from Xenopus laevis.
BioEssays
15
,
91
97
Mullins
M. C.
,
Hammerschmidt
M.
,
Haffter
P.
,
Nusslein-Volhard
C.
(
1994
)
Large-scale mutagenesis in the zebrafish: in search of genes controlling development in a vertebrate.
Curr. Biol
4
,
189
202
Nascone
N.
,
Mercola
M.
(
1995
)
An inductive role for the endoderm in Xenopus cardiogenesis.
Development
121
,
515
23
O'Reilly
M. A.
,
Smith
J. C.
,
Cunliffe
V.
(
1995
)
Patterning of the mesoderm in Xenopus: dose-dependent and synergistic effects of Brachyury and Pintallavis.
Development
121
,
1351
1359
Oxtoby
E.
,
Jowett
T.
(
1993
)
Cloning of the zebrafish krox-20 gene (krx-20) and its expression during hindbrain development.
Nucl. Acids Res
21
,
1087
1095
Papalopulu
N.
,
Kintner
C. R.
(
1993
)
Xenopus distal-less related homeobox genes are expressed in the developing forebrain and are induced by planar signals.
Development
117
,
961
975
Placzek
M.
,
Tessier-Lavigne
M.
,
Yamada
T.
,
Jessell
T.
,
Dodd
J.
(
1990
)
Mesodermal control of neural cell identity: floor plate induction by the notochord.
Science
250
,
985
989
Postlethwait
J. H.
,
Johnson
S. L.
,
Midson
C. N.
,
Talbot
W. S.
,
Gates
M.
,
Ballinger
E. W.
,
Africa
D.
,
Andrews
R.
,
Carl
T.
,
Eisen
J. S.
and et al (
1994
)
A genetic linkage map for the zebrafish.
Science
264
,
699
703
Puschel
A. W.
,
Gruss
P.
,
Westerfield
M.
(
1992
)
Sequence and expression pattern of pax-6 are highly conserved between zebrafish and mice.
Development
114
,
643
651
Puschel
A. W.
,
Westerfield
M.
,
Dressler
G. R.
(
1992
)
Comparative analysis of Pax-2 protein distributions during neurulation in mice and zebrafish.
Mech. Dev
38
,
197
208
Rebagliati
M. R.
,
Weeks
D. L.
,
Harvey
R. P.
,
Melton
D. A.
(
1985
)
Identification and cloning of localized maternal RNAs from Xenopus eggs.
Cell
42
,
769
777
Rivera-Perez
J. A.
,
Mallo
M.
,
Gendron-Maguire
M.
,
Gridley
T.
,
Behringer
R. R.
(
1995
)
Goosecoid is not an essential component of the mouse gastrula organizer but is required for craniofacial and rib development.
Development
121
,
3005
3012
Roelink
H.
,
Augsburger
A.
,
Heemskerk
J.
,
Korzh
V.
,
Norlin
S.
,
Ruiz
i. A. A.
,
Tanabe
Y.
,
Placzek
M.
,
Edlund
T.
,
Jessell
T. M.
and et al (
1994
)
Floor plate and motor neuron induction by vhh-1, a vertebrate homolog of hedgehog expressed by the notochord.
Cell
76
,
761
775
Rosa
F. M.
(
1989
).
Mix.1, a homeobox mRNA inducible by mesoderm inducers, is expressed mostly in the presumptive endodermal cells of Xenopus embryos.
Cell
57
,
965
974
Ruiz i Altaba
A.
(
1992
)
Planar and vertical signals in the induction and patterning of the Xenopus nervous system.
Development
115
,
67
80
Ruiz i Altaba
A.
(
1993
)
Induction and axial patterning of the neural plate: planar and vertical signals.
J. Neurobiol
24
,
1276
1304
Ruiz i Altaba
A.
,
Jessell
T. M.
(
1992
)
Pintallavis, a gene expressed in the organizer and midline cells of frog embryos: involvement in the development of the neural axis.
Development
116
,
81
93
Ruiz i Altaba
A.
,
Prezioso
V. R.
,
Darnell
J. E.
,
Jessell
T. M.
(
1993
)
Sequential expression of HNF-3a and HNF-3by embryonic organizing centers: the dorsal lip/node, notochord, and floor plate.
Mech. Dev
44
,
91
108
Ruiz i Altaba
A.
,
Jessell
T. M.
(
1993
)
Midline cells and the organization of the vertebrate neuraxis.
Current Opinion in Genetics & Development
3
,
633
640
Sasai
Y.
,
Lu
B.
,
Steinbeisser
H.
,
Geissert
D.
,
Gont
L. K.
,
De Robertis
E. M.
(
1994
)
Xenopus chordin: a novel dorsalizing factor activated by organizer-specific homeobox genes.
Cell
79
,
779
790
Sasaki
H.
,
Hogan
B. L. M.
(
1993
)
Differential expression of multiple forkhead related genes during gastrulation and axial pattern formation in the mouse embryo.
Development
118
,
47
59
Sater
A. K.
,
Jacobson
A. G.
(
1990
)
The role of the dorsal lip in the induction of heart mesoderm in Xenopuslaevis.
Development
108
,
461
470
Schier
A. F.
,
Neuhauss
S. C. F.
,
Harvey
M.
,
Malicki
J.
,
Solnica-Krezel
L.
,
Stainier
D. Y. R.
,
Zwartkruis
F.
,
Abdelilah
S.
,
Stemple
D. L.
,
Rangini
Z.
,
Yang
H.
,
Driever
W.
(
1996
)
Mutations affecting the development of the embryonic zebrafish brain.
Development
123
,
165
178
Schulte-Merker
S.
,
Hammerschmidt
M.
,
Beuchle
D.
,
Cho
K. W.
,
De Robertis
E. M.
,
Nusslein-Volhard
C.
(
1994
)
Expression of zebrafish goosecoid and no tail gene products in wild-type and mutant no tail embryos.
Development
120
,
843
852
Schulte-Merker
S.
,
Ho
R. K.
,
Herrmann
B. G.
,
Nusslein-Volhard
C.
(
1992
)
The protein product of the zebrafish homologue of the mouse T gene is expressed in nuclei of the germ ring and the notochord of the early embryo.
Development
116
,
1021
1032
Schulte-Merker
S.
,
VanEeden
F. J. M.
,
Halpern
M. E.
,
Kimmel
C. B.
,
Nusslein-Volhard
C.
(
1994
)
No tail (Ntl) is the zebrafish homologue of the mouse T (Brachyury) gene.
Development
120
,
1009
1015
Schultheiss
T. M.
,
Xydas
S.
,
Lassar
A. B.
(
1995
)
Induction of avian cardiac myogenesis by anterior endoderm.
Development
121
,
4203
4214
Seufert
D. W.
,
Hall
B. K.
(
1990
)
Tissue interactions involving cranial neural crest in cartilage formation in Xenopus laevis (Daudin).
Cell Diff. Dev
32
,
153
166
Shawlot
W.
,
Behringer
R. R.
(
1995
)
Requirement for Lim1 in head-organizer function.
Nature
374
,
425
30
Shih
J.
,
Keller
R.
(
1992
)
The epithelium of the dorsal marginal zone of Xenopus has organizer properties.
Development
116
,
887
899
Slack
J. M. W.
,
Darlington
B. G.
,
Heath
J. K.
,
Godsave
S. F.
(
1988
)
Mesoderm induction in early Xenopus embryos by heparin binding growth factors.
Nature
326
,
197
200
Slack
J. M.
(
1994
)
Inducing factors in Xenopus early embryos.
Curr. Biol
4
,
116
26
Smith
J.
(
1995
)
Mesoderm-inducing factors and mesodermal patterning.
Curr. Opin. Cell. Biol
7
,
856
861
Smith
J. C.
,
Slack
J. M. W.
(
1983
)
Dorsalization and neural induction: properties of the organizer in Xenopus laevis.
J. Embryol. Exp. Morphol
78
,
299
317
Smith
J. C.
,
Price
B. M.
,
Green
J. B.
,
Weigel
D.
,
Herrmann
B. G.
(
1991
)
Expression of a Xenopus homolog of Brachyury (T) is an immediate-early response to mesoderm induction.
Cell
67
,
79
87
Solnica-Krezel
L.
,
Schier
A. F.
,
Driever
W.
(
1994
)
Efficient recovery of ENU-induced mutations from the zebrafish germline.
Genetics
136
,
1401
1420
Stachel
S. E.
,
Grunwald
D. J.
,
Myers
P. Z.
(
1993
)
Lithium perturbation and goosecoid expression identify a dorsal specification pathway in the pregastrula zebrafish.
Development
117
,
1261
1274
Stainier
D. Y.
,
Weinstein
B. M.
,
Detrich
H. W.
3rd
,
Zon
L. I.
,
Fishman
M. C.
(
1995
)
Cloche, an early acting zebrafish gene, is required by both the endothelial and hematopoietic lineages.
Development
121
,
3141
3150
Strähle
U.
,
Blader
P.
,
Henrique
D.
,
Ingham
P. W.
(
1993
)
Axial, a zebrafish gene expressed along the developing body axis, shows altered expression in cyclops mutant embryos.
Genes Dev
7
,
1436
1446
Taira
M.
,
Jamrich
M.
,
Good
P. J.
,
Dawid
I. B.
(
1992
)
The LIM domain-containing homeo box gene Xlim-1 is expressed specifically in the organizer region of Xenopus gastrula embryos.
Genes & Development
6
,
356
366
Talbot
W. S.
,
Trevarrow
B.
,
Halpern
M. E.
,
Melby
A. E.
,
Farr
G.
,
Postlethwait
J. H.
,
Jowett
T.
,
Kimmel
C. B.
,
Kimelman
D.
(
1995
)
A homeobox gene essential for zebrafish notochord development.
Nature
378
,
150
157
Thisse
C.
,
Thisse
B.
,
Halpern
M. E.
,
Postlethwait
J. H.
(
1994
)
Goosecoid expression in neurectoderm and mesendoderm is disrupted in zebrafish cyclops gastrulas.
Dev. Biol
164
,
420
9
Thisse
C.
,
Thisse
B.
,
Schilling
T. F.
,
Postlethwait
J. H.
(
1993
)
Structure of the zebrafish snail1 gene and its expression in wild-type, spadetail and no tail mutant embryos.
Development
119
,
1203
15
Toyama
R.
,
Oconnell
M. L.
,
Wright
C. V. E.
,
Kuehn
M. R.
,
Dawid
I. B.
(
1995
)
Nodal induces ectopic goosecoid and lim1 expression and axis duplication in zebrafish.
Development
121
,
383
391
van Straaten
H. W. M.
,
Hekking
J. W. M.
,
Wiertz-Hoessels
E. L.
,
Thors
F.
,
Drukker
J.
(
1988
)
Effects of the notochord on the differentiation of a floor plate area in the neural tube of the chick embryo.
Anat. Embryol
177
,
317
324
van Straaten
H. W. M.
,
Hekking
J. W. M.
(
1991
)
Development of floor plate, neurons and axonal outgrowth pattern in the early spinal cord of the notochord-deficient chick embryo.
Anat. Embryol
184
,
55
63
von Dassow
G.
,
Schmidt
J. E.
,
Kimelman
D.
(
1993
)
Induction of the Xenopus organizer: expression and regulation of Xnot, a novel FGF and activin-regulated homeo box gene.
Genes Dev
7
,
355
66
Wachtler
F.
,
Jacob
H. J.
,
Jacob
M.
,
Christ
B.
(
1984
)
The extrinsic ocular muscles in birds are derived from the prechordal plate.
Naturwissenschaften
71
,
379
80
Weinberg
E. S.
,
Allende
M. L.
,
Kelly
C. S.
,
Abdelhamid
A.
,
Murakami
T.
,
Andermann
P.
,
Doerre
O. G.
,
Grunwald
D. J.
,
Riggleman
B.
(
1996
)
Developmental regulation of zebrafish myoD in wild-type, no tail and spadetail embryos.
Development
122
,
271
280
Weinstein
D. C.
,
Ruiz i Altaba
A.
,
Chen
W. S.
,
Hoodless
P.
,
Prezioso
V. R.
,
Jessell
T. M.
,
Darnell
J. E.
Jr
(
1994
)
The winged-helix transcription factor HNF-3 beta is required for notochord development in the mouse embryo.
Cell
78
,
575
88
Westerfield
M.
(
1994
)
The Zebrafish Book.
University of Oregon Press
,
Oregon
Wilson
V.
,
Manson
L.
,
Skarnes
W. C.
,
Beddington
R. S.
(
1995
).
The T gene is necessary for normal mesodermal morphogenetic cell movements during gastrulation.
Development
121
,
877
886
Wilson
V.
,
Rashbass
P.
,
Beddington
R. S.
(
1993
)
Chimeric analysis of T (Brachyury) gene function.
Development
117
,
1321
13
Wright
C. V. E.
,
Schnegelsberg
P.
,
De Robertis
E. M.
(
1988
)
Xlhbox8: a novel Xenopus homeoprotein restricted to a narrow band of endoderm.
Development
105
,
787
794
Yamada
G.
,
Mansouri
A.
,
Torres
M.
,
Stuart
E. T.
,
Blum
M.
,
Schultz
M.
,
De Robertis
E. M.
,
Gruss
P.
(
1995
)
Targeted mutation of the murine goosecoid gene results in craniofacial defects and neonatal death.
Development
121
,
2917
2922
Yan
Y.-L.
,
Hatta
K.
,
Riggleman
B.
,
Postlethwait
J. H.
(
1995
)
Expression of a type II collagen gene in the zebrafish embryonic axis.
Dev. Dynam
203
,
363
376
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