Mutations in the Tbx5 transcription factor cause heart septal defects found in human Holt-Oram Syndrome. The complete extent to which Tbx5 functions in heart development, however, has not been established. Here we show that, in Xenopus embryos, Tbx5 is expressed in the early heart field, posterior to the cardiac homeobox transcription factor, Nkx2.5. During morphogenesis, Tbx5 is expressed throughout the heart tube except the anterior portion, the bulbus cordis. When Tbx5 activity is antagonized with a hormone-inducible, dominant negative version of the protein, the heart fails to develop. These results suggest that, in addition to its function in heart septation, Tbx5 has a more global role in cardiac specification and heart development in vertebrate embryos.

Reference

Badiani
P.
,
Corbella
P.
,
Kioussis
D.
,
Marvel
J.
,
Weston
K.
(
1994
)
Dominant-interfering alles define arole for c-Myb in T-cell development.
Genes Dev
8
,
770
782
Bamshad
M.
,
Lin
R. C.
,
Law
D. J.
,
Watkins
W. S.
,
Krakowiak
P. A.
,
Moore
M. E.
,
Franceschini
P.
,
Lala
R.
,
Holmes
l. B.
,
Gebuhr
T. C.
,
Bruneau
B. G.
,
Schinzel
A.
,
Seidman
J. G.
,
Seidman
C. E.
,
Jorde
L. B.
(
1997
)
Mutations in human TBX3 alter limb, apocrine and genital development in ulnar-mammary syndrome.
Nature Gen
16
,
311
315
Basson
C. T.
,
Bachinsky
D. R.
,
Lin
R. C.
,
Levi
T.
,
Elkins
J. A.
,
Soults
J.
,
Grayzel
D.
,
Kroumpouzou
E.
,
Traill
T. A.
,
Leblanc-Straceski
J.
,
Renault
B.
,
Kucherlapati
R.
,
Seidman
J. G.
,
Seidman
C. E.
(
1997
)
Mutations in human Tbx5 cause limb and cardiac malformation in Holt-Oram syndrome.
Nature Gen
15
,
30
35
Basson
C. T.
,
Cowley
G. S.
,
Solomon
S. D.
,
Weissman
B.
,
Poznanski
A. K.
,
Traill
T. A.
,
Seidman
J. G.
,
Seidman
C. E.
(
1994
)
The clinical and genetic spectrum of the Holt-Oram syndrome (Heart-Hand syndrome).
New Eng. J. Med
330
,
885
891
Biben
C.
,
Harvey
R. P.
(
1997
)
Homeodomain factor Nkx2-5 controls left/right assymetric expression of bHLH gene eHAND during murine heart development.
Genes Dev
11
,
1357
1369
Chambers
A. E.
,
Logan
M.
,
Kotecha
S.
,
Towers
N.
,
Sparrow
D.
,
Mohun
T. J.
(
1994
)
The RSRF/MEF2 protein SL1 regulates cardiac muscle-specific transcription of a myosin light-chain gene in Xenopus embryos.
Genes Dev
8
,
1324
1334
Chapman
D. L.
,
Garvey
N.
,
Hancock
S.
,
Alexiou
M.
,
Agulnik
S. I.
,
Gibson-Brown
J. J.
,
Cebra-Thomas
J.
,
Bollag
R. J.
,
Silver
L. M.
,
Papaioannou
V. E.
(
1996
)
Expression of the T-box family genes, Tbx1-Tbx5, during early mouse development.
Dev. Dyn
206
,
379
390
Chapman
D. L.
,
Papaioannou
V. E.
(
1998
)
Three neural tubes in mouse embryos with mutations in the T-box gene Tbx6.
Nature
391
,
695
697
Chen
J. N.
,
Fishman
M. C.
(
1996
)
Zebrafish tinman homolog demarcates the heart field and initiates myocardial differentiation.
Development
122
,
3809
3816
Cleaver
O.
,
Tonissen
K. F.
,
Saha
M. S.
,
Krieg
P. A.
(
1997
)
Neovascularization of the Xenopus embryo.
Dev. Dyn
210
,
66
77
Cleaver
O. B.
,
Patterson
K. D.
,
Krieg
P. A.
(
1996
).
Overexpression of the tinman -related genes XNkx-2.5 and XNkx-2.3 in Xenopus embryos results in myocardial hyperplasia.
Development
122
,
3549
3556
Conlon
F. L.
,
Sedgwick
S. G.
,
Weston
K. M.
,
Smith
J. C.
(
1996
)
Inhibition of Xbra transcription activation causes defects in mesodermal patterning and reveals autoregulation of Xbra in dorsal mesoderm.
Development
122
,
2427
2435
Danielian
P. S.
,
White
R.
,
Lees
J. A.
,
Parker
M. G.
(
1992
)
Identification of a conserved region required for hormone dependent transcriptional activation by steroid hormone receptors.
EMBO J
11
,
1025
1033
de Graaf
(
1957
).
Investigations into the distribution of blood in the heart and aortic arches of Xenopus laevis (Daud.).
Exp. Biol
34
,
143
172
Devic
E.
,
Paquereau
L.
,
Vernier
P.
,
Knibiehler
B.
,
Audigier
Y.
(
1996
)
Expression of a new G protein-coupled receptor X-msr is associated with an endothelial lineage in Xenopus laevis.
Mech. Dev
59
,
129
140
Dorsky
R. I.
,
Rapaport
D. H.
,
Harris
W. A.
(
1995
)
Xotch inhibits cell differentiation in the Xenopus retina.
Neuron
14
,
487
496
Evans
S. M.
,
Yan
W.
,
Murillo
M. P.
,
Ponce
J.
,
Papalopulu
N.
(
1995
).
tinman, a Drosophila homeobox gene required for heart and visceral mesoderm specfication, may be represented by a family of genes in vertebrates: XNkx-2.3, a second vertebrate homologue of tinman.
Development
121
,
2889
2899
Fishman
M. C.
,
Chien
K. R.
(
1997
)
Fashioning the vertebrate heart: earlest embryonic decisions.
Development
124
,
2099
2117
Fishman
M. C.
,
Olson
E. N.
(
1997
)
Parsing the heart: genetic modules for organ assembly.
Cell
91
,
153
156
Fukuda-Taira
S.
(
1981
)
Location of pre-hepatic cells in the early developmental stages of quail embryos.
J. Embryol. Exp. Morphol
64
,
73
85
Gammill
L. S.
,
Sive
H.
(
1997
)
Identification of otx2 target genes and restrictions in ectodermal competence during Xenopus cement gland formation.
Development
124
,
471
481
Gibson-Brown
J. J.
,
Agulnik
S. I.
,
Silver
L. M.
,
Papaioannou
V. E.
(
1998
)
Expression of T-box genes Tbx2-Tbx5 during chick organogenesis.
Mech. Dev.
74
Gove
C.
,
Walmsley
M.
,
Nijjar
S.
,
Bertwistle
D.
,
Guille
M.
,
Partington
G.
,
Bomford
A.
,
Patient
R.
(
1997
).
Over-expression of GATA-6 in Xenopus embryos blocks the differentiation of heart precursors.
EMBO J
16
,
355
368
Han
K.
,
Manley
J. L.
(
1993
)
Functional domains of the Drosophila engrailed protein.
EMBO J
12
,
2723
2733
Harland
R. M.
(
1991
)
In situ hybridization: an improved whole mount method for Xenopus embryos.
Methods in Cell Biology
36
,
675
685
Harvey
R. P.
(
1996
)
NK-2 homeobox genes and heart development.
Dev. Biol
178
,
203
216
Heikinheimo
M.
,
Scandrett
J. M.
,
Wilson
D. B.
(
1994
)
Localization of transcription factor GATA-4 to regions of the mouse embryo involved in cardiac development.
Dev. Biol
164
,
361
373
Hiruma
T.
,
Hirakow
R.
(
1989
)
Epicardial formation in embryonic chick heart: computer aided reconstruction, scanning, and transmission electron microscopic studies.
Am. J. Anat
184
,
129
138
Ho
E.
,
Shimada
Y.
(
1978
)
Formation of the epicardium studied with the scanning electron microscope.
Dev. Biol
66
,
579
585
Holt
M.
,
Oram
S.
(
1960
)
Familial heart disease with skeletal malformations.
Br. Heart J
22
,
236
242
Horb
M. E.
,
Thomsen
G. H.
(
1997
)
A vegetally-localized Xenopus T-box gene specifies mesoderm and endoderm and is essential for mesoderm formation.
Development
124
,
1689
1698
Hurst
J. A.
,
Hall
C. M.
,
Baraitser
M.
(
1991
)
The Holt-Oram syndrome.
J. Med. Genet
28
,
406
410
Isaac
A.
,
Rodriguez-Esteban
C.
,
Ryan
A.
,
Altabef
M.
,
Tsukui
T.
,
Patel
K.
,
Tickle
C.
,
Izpisua-Belmonte
J. C.
(
1998
)
Tbx genes andlimb identity in chick embryo development.
Development
125
,
1867
1875
Jacobson
A. G.
(
1961
)
Heart determination in the Newt.
J. Exp. Zool
146
,
139
152
Jiang
Y.
,
Evans
T.
(
1996
)
The Xenopus GATA-4/5/6 genes are associated with cardiac specification and can regulate cardiac-specific transcription during embryogenesis.
Dev. Biol
174
,
258
270
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
Kelley
C.
,
Blumberg
H.
,
Zon
L. I.
,
Evans
T.
(
1993
)
GATA-4 is a novel transcription factor expressed in endocardium of the developing heart.
Dev
118
,
817
827
Kolm
P. J.
,
Sive
H. L.
(
1995
)
Efficient hormone-inducible protein function in Xenopus laevis.
Dev. Biol
171
,
267
272
Komuro
I.
,
Izumo
S.
(
1993
)
Csx: a murine homeobox-containing gene specifically expressed in the developing heart.
Proc. Natl. Acad. Sci. USA
90
,
8145
8149
Kuo
C. T.
,
Morrisey
E. E.
,
Anandappa
R.
,
Sigrist
K.
,
Lu
M. M.
,
Parmacek
M. S.
,
Sooudais
C.
,
Leiden
J. M.
(
1997
)
GATA4 transcription factor is required for ventral morphogenesis and heart tube formation.
Genes Dev
11
,
1048
1060
Laverriere
A. C.
,
MacNeill
C.
,
Mueller
C.
,
Poelmann
R. E.
,
Burch
J. B. E.
,
Evans
T.
(
1994
)
GATA-4/5/6, a subfamily of three transcription factors transcribed in developing heart and gut.
J. Biol. Chem
269
,
23177
23184
Li
H.
,
Tierney
C.
,
Wen
L.
,
Wu
J. Y.
,
Rao
Y.
(
1997
)
A single morphogenetic field gives rise to two retina primordia under the influence of the prechordal plate.
Development
124
,
603
615
Li
Q. Y.
,
Newbury-Ecob
R. A.
,
Terrett
J. A.
,
Wilson
D. I.
,
Curtis
A. R. J.
,
Yi
C. H.
,
Gebuhr
T.
,
Bullen
P. J.
,
Robson
S. C.
,
Strachan
T.
,
Bonnet
D.
,
Lyonnet
S.
,
Young
I. D.
,
Raeburn
J. A.
,
Buckler
A. J.
,
Law
D. J.
,
Brook
J. D.
(
1997
)
Holt-Oram syndrome is caused by mutations in TBX5, a member os the Brachyury (T) gene family.
Nature Gen
15
,
21
29
Lints
T. J.
,
Parsons
L. M.
,
Hartley
L.
,
Lyons
I.
,
Harvey
R. P.
(
1993
).
Nkx-2.5: a novel murine homeobox gene expressed in early heart progenitor cells and their myogenic descendants.
Development
119
,
419
431
Lustig
K. D.
,
Kroll
K. L.
,
Sun
E. E.
,
W. K. M.
(
1996
)
Expression cloning of a Xenopus T-related gene (Xombi) involved in mesodermal patterning and blastopore lip formation.
Development
122
,
4001
4012
Lyons
G. E.
(
1996
)
Vertebrate heart development.
Curr. Opin. Gen. Dev
6
,
454
460
Lyons
I.
,
Parsons
L. M.
,
Hartley
L.
,
Li
R.
,
Andrews
J. E.
,
Robb
L.
,
Harvey
R. P.
(
1995
)
Myogenic and morphogenetic defects in the heart tubes of murine embryos lacking the homeo box gene Nkx2-5.
Genes Dev
9
,
1654
1666
Markwald
R.
,
Eisenberg
C.
,
Eisenberg
L.
,
Trusk
T.
,
Sugi
Y.
(
1996
)
Epithelial-Mesenchymal transformations in early avian heart development.
Acta Anat
156
,
173
186
Mattioni
T.
,
Louvion
J. F.
,
Picard
D.
(
1994
)
Regulation of protein activities by fusion to steroid binding domains.
Methods in Cell Biology
43
,
335
352
Mohun
T.
,
Sparrow
D.
(
1997
)
Early steps in vertebrate cardiogenesis.
Curr. Opin. Gen. Dev
7
,
628
633
Molkentin
J. D.
,
Lin
Q.
,
Duncan
S. A.
,
Olson
E. N.
(
1997
)
Requirement of the transcription factor GATA4 for heart tube formation and ventral morphogenesis.
Genes Dev
11
,
1061
1072
Morrisey
E. E.
,
Ip
H. S.
,
Lu
M. M.
,
Parmacek
M. S.
(
1996
)
GATA-6: a zinc finger transcription factor that is expressed in multiple cell lineages derived from lateral mesoderm.
Dev. Biol
177
,
309
322
Newbury-Ecob
R. A.
,
Leanage
R.
,
Raeburn
J. A.
,
Young
I. D.
(
1996
)
Holt-Oram syndrome: a clinical genetic study.
J. Med. Genet
33
,
300
307
Newman
C. S.
,
Chia
F.
,
Krieg
P. A.
(
1997
)
The XHex homeobox gene is expressed during development of the vascular endothelium: overexpression leads to an increase in vascular endothelial cell number.
Mech. Dev
66
,
83
93
Ohuchi
H.
,
Takeuchi
J.
,
Yoshioka
H.
,
Ishimaru
Y.
,
Ogura
K.
,
Takahashi
N.
,
Ogura
T.
,
Noji
S.
(
1998
)
Correlation of wing-leg identity in ectopic FGF-induced chimeric limbs with the differential expresison of chick Tbx5 and Tbx4.
Development
125
,
51
60
Papaioannou
V. E.
,
Silver
L. M.
(
1998
)
The T-box gene family.
BioEssays
20
,
9
19
Papalopulu
N.
,
Kintner
C.
(
1996
)
A Xenopus gene, Xbr-1, defines a novel class of homeobox genes and is expressed in the dorsal ciliary margin of the eye.
Dev. Biol
174
,
104
114
Ryan
K.
,
Garrett
N.
,
Mitchel
A.
,
Gurdon
J. B.
(
1996
)
Eomesodermin, a key early gene in Xenopus mesoderm differentiation.
Cell
87
,
989
1000
Sater
A.
,
Jacobson
A.
(
1990
)
The restriction of the heart morphogenetic field in Xenopus laevis.
Dev. Biol
140
,
328
336
Schott
J.-J.
,
Benson
D. W.
,
Basson
C. T.
,
Pease
W.
,
Silberbach
G. M.
,
Moak
J. P.
,
Maron
B. J.
,
Seidman
C. E.
,
Seidman
J. G.
(
1998
)
Congentital heart disease caused by mutations in the transcription factor Nkx2-5.
Science
281
,
108
111
Sebedzija
G. N.
,
Chen
J. N.
,
Fishman
M. C.
(
1998
)
Regulation in the heart field of zebrafish.
Development
125
,
1095
1101
Simon
H. G.
,
Kittappa
R.
,
Khan
P. A.
,
Tsilfidis
C.
,
Liversage
R. A.
,
Appenheimer
S.
(
1997
)
A novel family of T-box genes in urodele amphibian limb development and regeneration: candidate genes involved in vertebrate forelimb/hindlimb patterning.
Development
124
,
1355
1366
Smith
A. T.
,
Sack
G. H.
,
Taylor
G. T.
(
1979
)
Holt-Oram Syndrome.
J. Pediatrics
95
,
538
543
Smith
D. F.
,
Toft
D. O.
(
1993
)
Steroid receptors and their associated proteins.
Mol. Endo
7
,
4
11
Smith
J. C.
(
1997
)
Brachyury and the T-box genes.
Curr. Opin. Gen. Dev
7
,
474
480
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
Stainier
D. Y. R.
,
Lee
R. K.
,
Fishman
M. C.
(
1993
)
Cardiovascular development in the zebrafish. I. Myocardial fate map and heart tube formation.
Development
119
,
31
40
Stennard
F.
,
Carnac
G.
,
Gurdon
J. B.
(
1996
)
A Xenopus T-box gene, antipodean, encodes a vegetally-localized maternal mRNA that can trigger mesoderm formation.
Development
122
,
4179
4188
Tada
M.
,
O'Reilly
M. A. J.
,
Smith
J. C.
(
1997
)
Analysis of competence and of Brachyury autoinduction by use of hormone-inducible Xbra.
Development
124
,
2225
2234
Tonissen
K. F.
,
Drysdale
T. A.
,
Lints
T. J.
,
Harvey
R. P.
,
Krieg
P. A.
(
1994
).
XNkx-2.5, a Xenopus gene related to Nkx-2.5 and tinman: evidence for a conserved role in cardiac development.
Dev. Biol
162
,
325
328
Tsai
M.
,
O'Malley
B. W.
(
1994
)
Molecular mechanisms of action of steroid/thyroid receptor superfamily members.
Annu. Rev. Biochem
63
,
451
486
Turner
D. L.
,
Weintraub
H.
(
1994
)
Expression of achaete-scute homolog 3 in Xenopus embryos converts ectodermal cells to a neural fate.
Genes Dev
8
,
1434
1447
Viragh
S.
,
Challice
C. E.
(
1973
)
Origin and differentiation of cardiac muscle cells in the mouse.
J. Ultrastruct. Res
42
,
1
24
Viragh
S.
,
Challice
C. E.
(
1981
)
The origin of the epicardium and the embryonic myocardial circulation in the mouse.
Anat. Rec
201
,
157
168
Wetts
R.
,
Fraser
S. E.
(
1988
)
Multipotent precursors can give rise to all major cell types of the frog retina.
Science
239
,
1142
1144
Wetts
R.
,
Serbedzija
G. N.
,
Fraser
S. E.
(
1989
)
Cell lineage analysis reveals multipotent precursors in the ciliary margin of the frog retina.
Dev. Biol
136
,
254
263
Wilens
S.
(
1955
)
The migration of heart mesoderm and associated areas in Amblystoma Punctatum.
J. Exp. Zool
129
,
579
605
Yutzey
K. E.
,
Gannon
M.
,
Bader
D.
(
1995
)
Diversification of cardiomyogenic cell lineages in vitro.
Dev. Biol
170
,
531
541
Zaret
K. S.
(
1996
)
Molecular genetics of early liver development.
Annu. Rev. Physiol
58
,
231
251
Zhang
J.
,
King
M. L.
(
1996
)
Xenopus VegT RNA is localized to the vegetal cortex during oogenesis and encodes a novel T-box transcription factor involved in mesodermal patterning.
Development
122
,
4119
4129
This content is only available via PDF.