Snail, a zinc finger protein, is required for the formation of the ventral furrow and the mesoderm during gastrulation of the Drosophila embryo. snail homologues have been cloned from Xenopus and mouse. We have isolated a zebrafish homologue of snail, designated sna-1. Like its Drosophila counterpart, Sna-1 protein is nuclear. Maternal and zygotic sna-1 transcripts are ubiquitously distributed in zebrafish embryos of cleavage and blastula stages. In gastrulating embryos, sna-1 is expressed in involuting cells of the germ ring, but not in those at the dorsal midline, the presumptive notochordal region. After involution, the expression is maintained in the paraxial mesoderm and becomes prominent in the muscle pioneer precursors, followed by expression at the posterior somite boundaries. Later, sna-1 is expressed in neural crest and mesodermal derivatives of the head region. Sna-1 expression is induced in animal cap cells by activin A. The early sna-1 expression pattern in gastrulating zebrafish no tail (ntl) mutant embryos is normal except a reduction in the level of sna-1 transcription, suggesting that Ntl protein is not the key activator of sna-1 transcription in vivo, but might be involved in the enhancement or maintenance of sna-1 transcription. Data obtained in studies with ectopic ntl expression support this model.

REFERENCES

Amaya
E.
,
Musci
T. J.
,
Kirschner
M. W.
(
1991
).
Expression of a dominant negative mutant of the FGF receptor disrupts mesoderm formation in Xenopus embryos.
Cell
66
,
257
270
Boulay
J. L.
,
Dennefels
C.
,
Alberga
A.
(
1987
).
The Drosophila developmental gene snail encodes a protein with nucleic acid binding fingers.
Nature
330
,
395
398
Bronner-Fraser
M.
,
Artinger
M.
,
Muschler
J.
,
Horwitz
A. F.
(
1992
).
Developmentally regulated expression of6 integrin in avian embryos.
Development
115
,
197
211
Chesley
P.
(
1935
).
Development of the short-tailed mutation in the house mouse.
J. Exp. Zool
70
,
429
459
Collodi
P.
,
Yuto
K.
,
Ernst
T.
,
Miranda
C.
,
Buhler
D. R.
,
Barnes
D. W.
(
1992
).
Culture of cells from zebrafish (Brachydanio rerio) embryo and adult tissues.
Cell Biol. Tox
8
,
43
61
Cunliffe
V.
,
Smith
J. C.
(
1992
).
Ectopic mesoderm formation in Xenopus embryos caused by widespread expression of a Brachyury homologue.
Nature
358
,
427
430
Driever
W.
,
Siegel
V.
,
Nusslein-Volhard
C.
(
1990
).
Autonomousdetermination of anterior structures in the early Drosophila embryo by the bicoid morphogen.
Development
109
,
811
820
Ekker
M.
,
Wegner
J.
,
Akimenko
M. A.
,
Westerfield
M.
(
1992
).
Coordinate expression of three zebrafish engrailed genes.
Development
116
,
1001
1010
Felsenfeld
A. L.
,
Curry
M.
,
Kimmel
C. B.
(
1991
).
The fub-1 mutation blocks initial myofibril formation in zebrafish muscle pioneer cells.
Dev. Biol
148
,
23
30
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
,
1
20
Hatta
K.
,
BreMiller
R.
,
Westerfield
M.
,
Kimmel
C.B.
(
1991
).
Diversity of expression of engrailed -like antigens in zebrafish.
Development
112
,
821
832
Hemmati-Brivanlou
A.
,
Melton
D. A.
(
1992
).
A truncated activin receptor inhibits mesoderm induction and formation of axial structures in Xenopus embryos.
Nature
359
,
609
614
Herrmann
B. G.
,
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
Ho
R. K.
,
Kane
D. A.
(
1990
).
Cell-autonomous action of zebrafish spt-1 mutation in specific mesodermal precursors.
Nature
348
,
728
730
Hopwood
N.
,
Pluck
A.
,
Gurdon
J. B.
(
1989
).
A Xenopus mRNA related to Drosophila twist is expressed in response to induction in the mesoderm and the neural crest.
Cell
59
,
893
903
Keynes
R. J.
,
Stern
C. D.
(
1984
).
Segmentation in the vertebrate nervous system.
Nature
310
,
786
789
Kimmel
C. B.
,
Kane
D. A.
,
Walker
C.
,
Warga
R. M.
,
Rothmann
M. A.
(
1989
).
A mutation that changes cell movement and cell fate in the zebrafish embryo.
Nature
337
,
358
362
Kimmel
C. B.
,
Warga
R. M.
,
Schilling
T. F.
(
1990
).
Origin and organization of the zebrafish fate map.
Development
108
,
581
594
Laemmli
U. K.
(
1970
).
Cleavage of structural proteins during the assembly of the head of bacteriophage T4.
Nature
227
,
680
685
Layer
P. G.
,
Alber
R.
,
Rathjen
F. G.
(
1988
).
Sequential activation of butyrylcholinesterase in rostral half somites and acetylcholinesterase in motoneurones and myotomes preceding growth of motor axons.
Development
102
,
387
396
McGinnis
W.
,
Krumlauf
R.
(
1992
).
Homeobox genes and axial patterning.
Cell
68
,
283
302
Myers
P. Z.
,
Eisen
J. S.
,
Westerfield
M.
(
1986
).
Development and axonal outgrowth of identified motoneurons in the zebrafish.
J. Neurosci
6
,
2278
2289
Nieto
M. A.
,
Bennet
M. F.
,
Sargent
M. G.
,
Wilkinson
D. G.
(
1992
).
Cloning and developmental expression of sna, a murine homologue of the Drosophila snail gene.
Development
116
,
227
237
Raible
D. W.
,
Wood
A.
,
Hodson
W.
,
Henion
P. D.
,
Weston
J.A.
,
Eisen
J. S.
(
1992
).
Segregation and early dispersal of neural crest cells in the embryonic zebrafish.
Dev. Dynamics
195
,
29
42
Rickmann
M.
,
Fawcett
J. W.
,
Keynes
R. J.
(
1985
).
The migration of neural crest cells and the growth of motor axons through the rostral half of the chick embryo.
J. Embryol. Exp. Morph
90
,
437
455
Sargent
M. G.
,
Bennett
M. F.
(
1990
).
Identification in Xenopus of a structural homologue of the Drosophila gene snail.
Development
109
,
967
973
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
Smith
D. E.
,
Del Amo
F. F.
,
Gridley
T.
(
1992
).
Isolation of sna, a mouse gene homologous to the Drosophila genes snail and escargot: its expression pattern suggests multiple roles during postimplantation development.
Development
116
,
1033
1039
Smith
J. C.
(
1989
).
Mesoderm induction and mesoderm-inducing factors in early amphibian development.
Development
105
,
665
677
Smith
J. C.
,
Price
B. M. J.
,
Green
J. B. A.
,
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
Solursh
M.
,
Drake
C.
,
Meier
S.
(
1987
).
The migration of myogenic cells from the somite at the wing level in avian embryos.
Dev. Biol
102
,
509
513
St. Johnston
D.
,
Nusslein-Volhard
C.
(
1992
).
The origin of pattern and polarity in the Drosophila embryo.
Cell
68
,
201
219
Thisse
B.
,
Stoetzel
C.
,
Gorostiza-Thisse
C.
,
Schmitt-Perrin
F.
(
1988
).
Sequence of the twist gene and nuclear localization of its protein in endomesodermal cells of early Drosophila embryos.
EMBO J
7
,
2175
2183
Towbin
H.
,
Stacklin
T.
,
Gurdon
J.
(
1979
).
Electrophoretic transfer of protein from polyacrylamide gels to nitrocellulose sheets: Procedure and some applications.
Proc. Natl. Acad. Sci. USA
76
,
4350
4357
Warga
R. M.
,
Kimmel
C. B.
(
1990
).
Cell movements during epiboly and gastrulation in zebrafish.
Development
108
,
569
580
Whiteley
M.
,
Nogushi
P. D.
,
Sensabaugh
S. M.
,
Odenwald
W. F.
,
Kassis
J. A.
(
1992
).
The Drosophila gene escargot encodes a zinc finger motif found in snail- related genes.
Mech. Dev
36
,
117
127
Wolf
C.
,
Thisse
C.
,
Stoetzel
C.
,
Thisse
B.
,
Gerlinger
P.
,
Perrin-Schmitt
F.
(
1991
).
The m-twist gene in Mus is expressed in subsets of mesodermal cells and is closely related to the Xenopus X-twi and the Drosophilatwist genes.
Dev. Biol
143
,
363
373
Yanagisawa
K. O.
,
Fufimoto
H.
,
Urshihara
H.
(
1981
).
Effects of the Brachyury (T) mutation on morphogenetic movement in the mouse embryo.
Dev. Biol
87
,
242
248
This content is only available via PDF.