During mouse development, the homeobox-containing gene En-1 is specifically expressed across the mid-hindbrain junction, the ventral ectoderm of the limb buds, and in regions of the hindbrain, spinal cord, somites and somite-derived tissues. To address the function of En-1 during embryogenesis, we have generated mice homozygous for a targeted deletion of the En-1 homeobox. En-1 mutant mice died shortly after birth and exhibited multiple developmental defects. In the brains of newborn mutants, most of the colliculi and cerebellum were missing and the third and fourth cranial nerves were absent. A deletion of midhindbrain tissue was observed as early as 9.5 days of embryonic development and the phenotype resembles that previously reported for Wnt-1 mutant mice. In addition, patterning of the forelimb paws and sternum was disrupted, and the 13th ribs were truncated. The results of these studies suggest a cell autonomous role for En-1 in generation and/or survival of mid-hindbrain precursor cells and also a non-cell autonomous role in signalling normal development of the limbs and possibly sternum.

REFERENCES

REFERENCES
Alvarado-Mallart
R.-M.
,
Martinez
S.
,
Lance-Jones
C. C.
(
1990
)
Pluripotentiality of the 2-day-old avian germinative neuroepithelium.
Dev. Biol
139
,
75
88
Bally-Cuif
L.
,
Alvarado-Mallart
R.-M.
,
Darnell
D. K.
,
Wassef
M.
(
1992
)
Relationship between Wnt - 1 and En - 2 expression domains during early development of normal and ectopic met-mesencephalon.
Development
115
,
999
1009
Bejsovec
A.
,
Martinez-Arias
A.
(
1991
)
Roles of wingless in patterning the larval epidermis of Drosophila.
Development
113
,
471
485
Boer
H. P.
,
Potten
H.
,
Adra
C. N.
,
Jardine
K.
,
Mullhofer
G.
,
McBurney
M. W.
(
1990
)
Polymorphisms in the coding and noncoding regions of murine Pgk - 1 alleles.
Biochem. Genet
28
,
299
308
Brower
D.
(
1986
)
Engrailed gene expression in Drosophila imaginal discs.
EMBO J
5
,
2649
2656
Carpenter
E. M.
,
Goddard
J. M.
,
Chisaka
O.
,
Manley
N.
,
Capecchi
M. R.
(
1993
)
Loss of Hox - a1 (Hox - 1. 6) function results in the reorganization of the murine hindbrain.
Development
118
,
1063
1077
Chen
J. M.
(
1952
)
Studies on the morphogenesis of the mouse sternum. I. Normal embryonic development.
J. Anat
86
,
373
386
Chen
J. M.
(
1953
)
Studies on the morphogenesis of the mouse sternum. III. Experiments on the closure and segmentation of the sternal bands.
J. Anat
87
,
130
149
Coleman
K. G.
,
Poole
S. J.
,
Weir
M. P.
,
Soeller
W. C.
,
Kornberg
T. B.
(
1987
)
The invected gene of Drosophila: sequence analysis and expression studies reveal a close kinship to the engrailed gene.
Genes Dev
1
,
19
28
Conlon
R. A.
,
Rossant
J.
(
1992
)
Exogenous retinoic acid rapidly induces anterior ectopic expression of murine Hox - 2 genes in vivo.
Development
116
,
357
368
Davidson
D.
,
Graham
E.
,
Sime
C.
,
Hill
R.
(
1988
)
A gene with sequence similarity to Drosophila engrailed is expressed during the development of the neural tube and vertebrae in the mouse.
Development
104
,
305
316
Davis
C. A.
,
Noble-Topham
S. E.
,
Rossant
J.
,
Joyner
A. L.
(
1988
)
Expression of the homeo box containing gene En - 2 delineates a specific region of the developing mouse brain.
Genes Dev
2
,
361
371
Davis
C. A.
,
Holmyard
D. P.
,
Millen
K. J.
,
Joyner
A. L.
(
1991
)
Examining pattern formation in mouse, chicken and frog embryos with an En-specific antiserum.
Development
111
,
287
298
Davis
C. A.
,
Joyner
A. L.
(
1988
)
Expression patterns of the homeo box-containing genes En - 1 and En - 2 and the proto-oncogene int - 1 diverge during mouse development.
Genes Dev
2
,
1736
1744
DiNardo
S.
,
Kuner
J. M.
,
Theis
J.
,
O'Farrell
P. H.
(
1985
)
Development of embryonic pattern in D. melanogaster as revealed by accumulation of the nuclear engrailed protein.
Cell
43
,
59
69
DiNardo
S.
,
Sher
E.
,
Heemskerk-Jongens
J.
,
Kassis
J. A.
,
O'Farrell
P. H.
(
1988
)
Two-tiered regulation of spatially patterned engrailed gene expression during Drosophila embryogenesis.
Nature
332
,
604
609
Dolle
P.
,
Lufkin
T.
,
Krumlauf
R.
,
Mark
M.
,
Duboule
D.
,
Chambon
P.
(
1993
)
Local alterations of Krox - 20 and Hox gene expression in the hindbrain suggest loss of rhombomeres 4 and 5 in homozygote null Hoxa - 1 (Hox - 1. 6) mutant embryos.
Proc. Natl. Acad. Sci. USA
90
,
7666
7670
Dolle
P.
,
Dierich
A.
,
LeMeur
M.
,
Schimang
L.
,
Schuhbaur
B.
,
Chambon
P.
,
Duboule
D.
(
1993
)
Disruption of the Hoxd-13 gene induces localized heterochrony leading to mice with neotenic limbs.
Cell
75
,
431
441
Doetschman
T. C.
,
Eistetter
H.
,
Katz
M.
,
Schmidt
W.
,
Kemler
R.
(
1985
)
The in vitro development of blastocyst-derived embryonic stem cell lines: formation of visceral yolk sac, blood islands and myocardium.
J. Embryol. Exp. Morph
87
,
27
45
Goetinck
P. F.
(
1964
)
Studies on limb morphogenesis. II. Experiments with the polydactylous mutant eudiplopodia.
Dev. Biol
10
,
71
91
Gurdon
J. B.
(
1992
)
The generation of diversity and pattern in animal development.
Cell
68
,
185
199
Hallonet
M. E. R.
,
Teillet
M.-A.
,
Le Douarin
N. M.
(
1990
)
A new approach to the development of the cerebellum provided by the quail-chick marker system.
Development
108
,
19
31
Heemskerk
J.
,
DiNardo
S.
,
Kostriken
R.
,
O'Farrell
P. H.
(
1991
)
Multiple modes of engrailed regulation in the progression towards cell fate determination.
Nature
352
,
404
410
Joyner
A. L.
,
Kornberg
T.
,
Coleman
K. G.
,
Cox
D.
,
Martin
G. R.
(
1985
)
Expression during embryogenesis of a mouse gene with sequence homology to the Drosophilaengrailed gene.
Cell
43
,
29
37
Joyner
A. L.
,
Martin
G. R.
(
1987
)
En - 1 and En - 2, two mouse genes with sequence homology to the Drosophilaengrailed gene: expression during embryogenesis.
Genes Dev
1
,
29
38
Joyner
A. L.
,
Skarnes
W. C.
,
Rossant
J.
(
1989
)
Production of a mutation in the mouse En - 2 gene by homologous recombination in embryonic stem cells.
Nature
338
,
153
156
Joyner
A. L.
,
Herrup
K.
,
Auerbach
A.
,
Davis
C. A.
,
Rossant
J.
(
1991
)
Subtle cerebellar phenotype in mice homozygous for a targeted deletion of the En - 2 homeobox.
Science
251
,
1239
1243
Klingensmith
J.
,
Noll
E.
,
Perrimon
N.
(
1989
)
The segment polarity phenotype of Drosophila involves differential tendencies toward transformation and cell death.
Dev. Biol
134
,
130
145
Kornberg
T.
(
1981
)
Engrailed: A gene controlling compartment and segment formation in Drosophila.
Proc. Natl. Acad. Sci. USA
78
,
1095
1099
Kornberg
T.
,
Siden
I.
,
O'Farrell
P.
,
Simon
M.
(
1985
)
The engrailed locus of Drosophila: in situ localization of transcripts reveals compartment-specific expression.
Cell
40
,
45
53
Logan
C.
,
Khoo
W. K.
,
Cado
D.
,
Joyner
A. L.
(
1993
)
Two enhancer regions in the mouse En - 2 locus direct expression to the mid/hindbrain region and mandibular myoblasts.
Development
117
,
905
916
Lufkin
T.
,
Mark
M.
,
Hart
C. P.
,
Dolle
P.
,
LeMeur
M.
,
Chambon
P.
(
1992
)
Homeotic transformation of the occipital bones of the skull by ectopic expression of a homeobox gene.
Nature
359
,
835
841
Lumsden
A.
,
Keynes
R.
(
1989
)
Segmental patterns of neuronal development in the chick hindbrain.
Nature
337
,
424
464
MacCabe
J. A.
,
Errick
J.
,
Saunders
J. W.
Jr
(
1974
)
Ectodermal control of the dorsoventral axis in the leg bud of the chick embryo.
Dev. Biol
39
,
69
82
Mansour
S. L.
,
Thomas
K. R.
,
Capecchi
M. R.
(
1988
)
Disruption of the proto-oncogene int - 2 in mouse embryo-derived stem cells: a general strategy for targeting mutations to non-selectable genes.
Nature
336
,
348
352
Mark
M.
,
Lufkin
T.
,
Vonesch
J.-L.
,
Ruberte
E.
,
Olivo
J. C.
,
Dolle
P.
,
Gorry
P.
,
Lumsden
A.
,
Chambon
P.
(
1993
)
Two rhombomeres are altered in Hoxa - 1 mutant mice.
Development
119
,
319
338
Martinez-Arias
A.
,
Baker
N. E.
,
Ingham
P. W.
(
1988
)
Role of segment polarity genes in the definition and maintenance of cell states in the Drosophila embryo.
Development
103
,
157
170
McGinnis
N.
,
Krumlauf
R.
(
1992
)
Homeobox genes and axial patterning.
Cell
68
,
283
302
McMahon
A. P.
,
Bradley
A.
(
1990
)
The Wnt - 1 (int - 1) proto-oncogene is required for development of a large region of the mouse brain.
Cell
62
,
1073
1085
McMahon
A. P.
,
Joyner
A. L.
,
Bradley
A.
,
McMahon
J. A.
(
1992
)
The midbrain-hindbrain phenotype of Wnt - 1 / Wnt - 1 mice results from stepwise deletion of engrailed-expressing cells by 9. 5 days postcoitum.
Cell
69
,
581
595
Millen
K.
,
Wurst
W.
,
Herrup
K.
,
Joyner
A. L.
(
1994
)
Abnormal embryonic cerebelar development and patterning of post-natal foliation in two Engrailed - 2 mutants.
Development
120
,
695
706
Nagy
A.
,
Rossant
J.
,
Nagy
R.
,
Abramow-Newerly
,
Roder
J. C.
(
1993
)
Derivation of completely cell culture-derived mice from early-passage embryonic stem cells.
Proc. Natl. Acad. Sci. USA
90
,
8424
8428
Parr
B. A.
,
Shea
M. J.
,
Vassileva
G.
,
McMahon
A. P.
(
1993
)
Mouse Wnt genes exhibit discrete domains of expression in the early embryonic CNS and limb buds.
Development
119
,
247
261
Ramirez-Solis
R.
,
Zheng
H.
,
Whiting
J.
,
Krumlauf
R.
,
Bradley
A.
(
1993
)
Hoxb - 4 mutant mice show homeotic transformation of a cervical vertebra and defects in the closure of the sternal rudiments.
Cell
73
,
273
294
Schmidt-Ott
U.
,
Technau
G. M.
(
1992
)
Expression of en and wg in the embryonic head and brain of Drosophila indicates a refolded band of seven segment remnants.
Development
116
,
111
125
Schneider-Maunoury
S.
,
Topilko
P.
,
Seitanidou
T.
,
Levi
G.
,
Cohen-Tannoudji
M.
,
Pournin
S.
,
Babinet
C.
,
Charney
P.
(
1993
)
A targed mutation in Krox - 20 results in alteration of rhombomeres 3 and 5 in the developing hindbrain.
Cell
75
,
119
1214
Simeone
A.
,
Acampora
D.
,
Gulisano
M.
,
Stornaiuolo
A.
,
Boncinelli
E.
(
1992
)
Nested expression domains of four homeobox genes in developing rostral brain.
Nature
358
,
687
690
Solursh
M.
(
1984
)
Ectoderm as a determinant of early tissue pattern in the limb bud.
Cell Diff
15
,
17
24
Swiatek
J. P.
,
Gridley
T.
(
1993
)
Perinatal lethalithy and defects in hindbrain development in mice homozygous for a targeted mutation of the zinc finger gene Krox - 20.
Genes Dev
7
,
2071
2084
Thomas
K. R.
,
Capecchi
M. R.
(
1990
)
Targeted disruption of the murine int - 1 proto-oncogene resulting in severe abnormalities in midbrain and cerebellar development.
Nature
346
,
847
850
Thomas
K. R.
,
Musci
T. S.
,
Neumann
P. E.
,
Capecchi
M. R.
(
1991
)
Swaying is a mutant allele of the proto-oncogene Wnt - 1.
Cell
67
,
969
976
Tybulewicz
V. L. J.
,
Crawford
C. E.
,
Jackson
P. K.
,
Bronson
R. T.
,
Mulligan
R. C.
(
1991
)
Neonatal lethality and lymphopoenia in mice with a homozygous disruption of the c - abl proto-oncogene.
Cell
65
,
1153
1163
Wilkinson
D. G.
,
Bailey
J. A.
,
McMahon
A. P.
(
1987
)
Expression of the proto-oncogene int - 1 is restricted to specific neural cells in the developing mouse embryo.
Cell
50
,
79
88
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