© 2000 American Heart Association, Inc.
Molecular Medicine |
Jumonji, a Nuclear Protein That Is Necessary for Normal Heart Development
From the Cardiovascular Research Center and Department of Anatomy (Y.L., A.J.S., R.B., B.M., G.E.L.), University of Wisconsin Medical School, Madison, Wis, and Institute of Molecular Medicine and Genetics, Department of Cell Biology and Anatomy (S.J.C.), Medical College of Georgia, Augusta, Ga. Present address of R.B. is Department of Nutritional Sciences, University of Arizona, Tucson, Ariz.
Correspondence to Gary E. Lyons, PhD, Department of Anatomy, University of Wisconsin Medical School, 1300 University Ave, Madison, WI 53706. E-mail gelyons{at}facstaff.wisc.edu
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Abstract—Jumonji (jmj) was cloned in a gene trap screen to identify and mutagenize genes important for heart development. To investigate the role of jmj in heart development, we generated mice homozygous for the jmj mutation. The jmj homozygous mouse embryos showed heart malformations, including ventricular septal defect, noncompaction of the ventricular wall, double-outlet right ventricle, and dilated atria. The jmj mutants died soon after birth, apparently as a result of respiratory insufficiency caused by rib and sternum defects in addition to the heart defects. In situ hybridization analyses suggested that cardiomyocytes were differentiated but developmental regulation of chamber-specific genes was defective in fetal hearts. Expression of jmj was detected in the myocardium, especially in the interventricular septum, ventricular wall, and outflow tract, which correlated well with the locations of defects observed in the hearts of mutant mice. Homozygous embryos failed to express the jmj transcript in all tissues except in the nervous system. Confocal microscopic examination using anti-JMJ antibodies indicated that the JMJ protein was localized in the nuclei of cells transfected with jmj. These data demonstrate that JMJ is a nuclear protein, which is essential for normal heart development and function.
Key Words: jumonji • cardiac abnormalities • gene trap
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Introduction |
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Cardiac development is a complex biological process requiring the integration of cell specification, differentiation, and morphogenesis. Many factors have been implicated in this process on the basis of their spatial and temporal expression patterns or their phenotypic effects when they are functionally inactivated in flies or mice.1 Transcription factors playing critical roles in early cardiac morphogenesis include MEF2C,2 GATA4,3 4 Nkx2.5,5 and others reviewed in Reference 6 ).
Identification of molecular pathways involved in normal heart development would lead to discovery of the genetic basis for human congenital heart disease. For example, congenital heart disease characterized by septal defects and abnormal atrioventricular conduction is caused by mutations in the transcription factor Nkx2.5.7 Another group of human cardiac defects referred to as CATCH-22 may be caused in part by mutation in a downstream gene of dHAND.8
A gene trap approach represents a versatile strategy by which genes that control developmental events can be identified and characterized while at the same time corresponding mutants can be produced. We have previously identified an ES cell clone that contains the jumonji (jmj) mutant allele by insertion of the gene trap vector, ßgeo.9 This clone showed high lacZ expression in in vitro–differentiated ES cardiomyocytes. Although the jmj gene has been identified and described as developmentally important in the liver, spleen, thymus, and nervous system,10 11 neither its role in the developing heart nor the molecular function of the JMJ protein is understood.
We generated jmj homozygous mutant mice to examine the function of JMJ in the developing heart. Morphological analyses of jmj mutants revealed abnormal heart development. Myocardium development was shown to be defective by cardiac marker gene analysis. All mutant mice died soon after birth. The jmj transcript was abolished in the homozygous embryos except in the nervous system, resulting in a tissue-specific disruption of jmj. The present study demonstrates that JMJ is a nuclear factor that is necessary for normal heart development.
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Materials and Methods |
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An expanded online Materials and Methods section containing details of the generation of the jmj mice, genotyping, cDNA cloning, in situ hybridization, morphological analyses, and antibody production is available at http://www.circresaha.org.
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Results |
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Generation of jmj Homozygous Mutant Mice and Genotyping
ßgeo was inserted 3' to the exon containing the translation initiation site, which was designated as exon 1 (Figure 1A
). Thus, all jmj mRNAs can
be replaced by ßgeo sequences except for the first 15 codons. To
genotype the offspring, the 3' flanking sequence of the trap
vector insertion site was cloned by inverse polymerase chain reaction
and designated as probe B. Probe B hybridized to an 8.0-kb band for
wild-type or a 3.3-kb band for trapped genomic DNA when a Southern blot
was performed (Figure 1B). Probe A, which was generated from the
5' RACE (rapid amplification of cDNA end)
product,9 hybridized to an 8-kb band for
wild-type or a 10.5-kb band for trapped genomic DNA (data not shown).
There were no live homozygotes among newborns, but all homozygous
embryos were alive until E18.5, suggesting that all homozygotes died
near birth (Table).
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To examine whether the homozygous gene trap insertion resulted in a
null mutation, total RNA from E16.5 embryos was subjected to Northern
blot analysis using a jmj cDNA as a probe.
jmj mRNA was not detected in the mutant embryo bodies
(Figure 1C
, lanes 1 and 2) when the membrane was exposed for up
to 2 days, whereas a 5.4-kb band was detected in wild-type embryos
(lanes 3 and 4). A faint band was observed after a 4-day exposure (data
not shown) because of the expression of jmj in the nervous
system (see below). jmj mRNA was detected in mutant brain
(lane 6) at a similar level to wild type (lane 5). Detailed in situ
hybridization (ISH) analyses indicated that the jmj
mRNA expression was abolished in all tissues except the nervous system
of homozygous embryos (see below). These data indicated that splicing
to exon 2 occurred in neurons, resulting in the wild-type
jmj transcript. lacZ expression was also observed
in the nervous system of heterozygous and homozygous embryos (see
online-only supplemental data at http://www.circresaha.org), suggesting
that both the splicing to exon 2 and the splicing to ßgeo occurred in
the nervous system.
jmj Is Expressed in the Normal Developing Heart but
Not in the Mutant Heart
ISH analysis was performed to analyze the
expression pattern of jmj in homozygous mutants (Figure 2). In wild-type embryos,
jmj was widely expressed, including the brain and
surrounding mesodermal tissues (A). In the mutant, jmj was
only detected in the spinal cord, telencephalon, and cranial ganglia at
E12.5 (C). The jmj transcript was not detected in any cell
type of the mutant embryo body at E13.5 except neurons (E). Similarly,
the normal expression of jmj at E17 (F) was not detected in
the mutant embryo except in the spinal cord and peripheral
ganglia (G). The sense probe did not show any specific hybridization (B
and H). These data indicated that the homozygous jmj mutant
allele abolished the jmj transcript in all tissues
except the nervous system.
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Northern blot analysis indicated that a single band of 5.4 kb
was observed in various adult mouse tissues after overnight exposure
(Figure 1D). jmj was highly expressed in the heart,
brain, thymus, and skeletal muscle when normalized to ß-actin.
Therefore, jmj is expressed in all stages of developing
hearts from the precardiac mesoderm to adult mouse hearts as indicated
by lacZ staining of heterozygous and ISH of wild-type
embryos (Figures 1D and 2 and online-only Figures 1 and 2
[see http://www.circresaha.org]).10 12
Knockout of jmj Resulted in Congenital Heart
Defects
jmj heterozygotes did not show any discernable
phenotypic abnormalities, but all homozygous embryos died at birth. All
homozygous embryos were smaller than their littermates, had open eyes,
and often exhibited edema. Morphology of E11- to E19-stage developing
hearts was examined by hematoxylin and eosin (H&E) staining (Figure 3), because homozygous embryos were alive
in utero until birth.
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At E11, wild-type and homozygous mutant hearts were
histologically indistinguishable (data not shown).
Transverse H&E–stained sections revealed that both the outflow tract
and the atrioventricular endocardial cushions had
formed normally. At E13, wild-type (Figures 3A-a and 3A-b) and
homozygous mutant (Figures 3A-c through 3A-f) hearts were
histologically distinguishable. The mutant embryos
exhibited double-outlet right ventricle (DORV) and a prominent
ventricular septal defect (VSD). The aorta normally exits
the left ventricle and the pulmonary trunk exits the right
ventricle. However, in the mutant (Figures 3A-c and 3A-e), both
the aorta and pulmonary vessels exit the right ventricle. There
was an abnormally deep interventricular groove (asterisks
in Figures 3A-c and 3A-e). Holes were evident within the
ventricular septum of the mutants (arrowheads in Figures 3A-e and 3A-f). The trabeculated walls of the left
and right ventricular chambers appeared to be of equal
thickness between the wild type and mutant (Figures 3A-b through
3A-d).
At E16, wild-type (Figures 3B-a through 3B-c) and mutant
(Figures 3B-d through 3B-f) hearts were macroscopically
distinguishable, as the mutant embryos were severely edematous (large
arrows in B-d). The mutant hearts exhibited an abnormally thin
trabeculated wall of both ventricular chambers
in addition to DORV and VSD (arrowheads in B-d and B-e). A higher-power
image of the ventricular wall indicates that the abnormally
thin myocardium in mutants was due to a deficiency of the
outer compact zone (arrows in B-f). Proliferation of myocytes at the
ventricular epicardial surface (the compact zone) from
E12.5 onward generates the thickened outer wall and contributes to the
muscular septum that separates these 2 chambers. At E19, the outer
compact zone of mutant hearts (Figures 3C-c and 3C-d) was absent
compared with wild type (Figures 3C-a and 3C-b). There was a
significant reduction in coronary vessels. The homozygous
embryos exhibited DORV (C-e and C-f). To test whether an increase in
programmed cell death could account for the thin myocardium
and VSD, in situ apoptosis assays (Oncor/Intergen) were
performed using heart sections from E12.5 to E17 embryos. No
significant increase in the number of apoptotic cells was
observed in the mutant myocardium compared with wild type
(Y. Lee, unpublished data, 2000).
A total of 16 homozygous embryos from E13 to E19 were analyzed for their heart defects. VSD and noncompaction of the ventricular wall were observed with full penetrance. DORV was observed in 14 of 16 homozygotes. The aortic and pulmonary valves and atrioventricular valves appeared to be normal. Enlarged right atria and edema were frequently seen, suggesting hemodynamic dysfunction.
A microscopic examination revealed that the lungs of homozygous
newborns did not inflate, suggesting the mice did not breathe after
birth. The gross morphology of the lung and diaphragm appeared to be
normal, but the ribcage and sternum were defective. The sternum is
fused by E14.5 in normal mouse embryos.13 However, in all
mutant embryos, the sternum still comprised 2 bones, known as "cleft
sternum" (small arrow in Figure 3B-d). Skeletal staining of
newborn mutants confirmed the defect in sternum fusion (Figure 4). Robust ossification of the sternum
was observed in wild-type embryos (A), whereas complete lack of
ossification was evident in the sternum of mutants (B). Ossification of
the ribcage in mutants was less than that of wild-type littermates.
These skeletal defects may contribute to respiratory insufficiency by
increasing chest wall compliance.
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Analysis of Cardiac Marker Gene Expression
The role of JMJ as a potential regulator of cardiac
muscle–specific gene expression was investigated using ISH. cRNA
probes hybridized to sections of E13 and E17 embryos were 
-myosin
heavy chain (MHC), ß-MHC, myosin light chain (MLC)2V, MLC2A,
-cardiac actin, atrial natriuretic factor
(ANF),14 dHAND and eHAND, MsxI and Msx2,1
vascular cell adhesion molecule, and superoxide dismutase. All of these
cardiac markers were expressed in mutant hearts. However, expression
levels of -MHC, ß-MHC, MLC2A, and ANF were affected in a way
suggesting that developmental regulation of these genes was disrupted
(Figure 5).
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The predominant expression of ß-MHC in the embryonic ventricle
normally switches to -MHC near birth in mice.15 The
mutant ventricle at E17 showed that the expression level of -MHC was
much lower (Figures 5A and 5B), whereas the expression level of
ß-MHC was higher than the wild type (data not shown). Expression of
ANF in the ventricle normally declines rapidly near birth, whereas
expression in the atrium is maintained.16 The ventricle of
E17 mutants exhibited a higher expression level of ANF than the wild
type, suggesting a defect in downregulation of ANF (Figures 5C and 5D). MLC2A is initially expressed throughout the tubular heart and
is downregulated in the ventricle during chamber
formation.14 However, expression levels of MLC2A in the
mutant ventricles were higher than those of wild-type ventricles from
E13 and E17 embryos (data not shown). MLC2V, normally expressed only in
the ventricle,14 was expressed in some regions of the
mutant atria (arrows in Figures 5F and 5H). MLC2V expression in
the mutant atria did not appear to coincide with regions of conductive
tissue. Sense cRNA probes did not show any hybridization to tissue
sections (data not shown). Other genes examined were expressed in a
similar pattern in the myocardium of mutant and wild-type
hearts (Y. Lee, unpublished data, 2000).
JMJ Is a Nuclear Factor
Immunostaining assays were performed using 2
polyclonal anti-peptide antibodies against JMJ (Figure 6). Nuclear staining of JMJ in
transfected Cos cells was observed using the antiserum Ab1 (A) or Ab2
(data not shown) under the confocal microscope. JMJ is associated with
chromatin during progression of the cell cycle from prophase (arrows in
panels A and B) to telophase (Y. Lee, unpublished data, 2000). Nuclear
localization was confirmed by immunostaining of Cos
cells transfected with jmj/pcDNA3.1 containing the Xpress
tag epitope using the Xpress tag antibody (Invitrogen) (panel C). Cos
cells transfected with the jmj-GFP plasmid showed nuclear
localization of JMJ (data not shown). Immunoprecipitation was performed
in NETN buffer17 using in vitro–translated
35S-labeled JMJ that was detected as a 150-kDa
band. Both anti-JMJ antibodies immunoprecipitated the in vitro
translated JMJ, whereas the preimmune serum did not, indicating the
specificity of these antibodies (Y. Lee, unpublished data, 2000). Both
anti-JMJ antibodies did not recognize JMJ in Western blot
analysis of either Cos cell extracts overexpressing JMJ or
tissue extracts (data not shown).
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Discussion |
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The phenotype of jmj mutants reveals a critical role for JMJ in normal heart development in mice. Cardiac function in the mutant embryos is likely to be severely compromised by the thin ventricular wall and the abnormal content of myocardial contractile proteins. In addition, VSD and DORV undoubtedly cause hemodynamic disturbances.
Cardiac Abnormalities in jmj Mutants
DORV is a heart defect that results from any perturbation that
affects normal cardiac looping, especially the second phase, when the
forming septa come into proper alignment.18 In mice, such
perturbations include targeted gene deletions of retinoid
receptors19 20 and transforming growth
factor-ß2.21 The perturbation in
repositioning and remodeling processes during looping may lead to DORV
in jmj mutants.
The ventricular septum is formed by 2 processes. The trabeculae condense at the interventricular groove. The medial walls of the expanding ventricles fuse together and grow inward, forming the major muscular portion of the septum. The poor development of the muscular septum in jmj homozygous embryos is most likely accounted for by the lack of ventricular wall expansion. Although the septum is the thickest portion of the ventricle in normal E14.5 embryos, in jmj mutants it appears to be a fenestrated thin wall with poor contribution from the compact zone of the ventricular wall. A subsequent lack of fusion of the endocardial cushions to the basal portion of this incomplete septum results in the observed VSD.
Vitamin A deficiency in embryos leads to a variety of heart defects.
The major defects in retinoid X receptor (RXR)–20 and
retinoic acid receptor double-mutant mice19 include
hypoplastic ventricular walls, VSD, dilated right atria,
and DORV, all of which overlap with jmj mutant
phenotypes. Therefore, it is conceivable that JMJ may share a
common molecular pathway with retinoids and transforming growth
factor-ß in developing hearts.
Abnormal Regulation of Cardiac-Specific Genes in jmj
Homozygous Mutant
The pattern of sarcomeric protein gene expression is tightly
regulated in a tissue- and developmental stage–specific manner.
Expression of cardiac-specific genes such as -MHC, MLC2V, and ANF is
regulated by several transcription factors, including Nkx2.5, GATA4,
and MEF2.5 17 22 Therefore, it is possible that JMJ may
interact with these transcription factors to modulate the target gene
expression. MLC2V was misexpressed in the mutant atrium. MLC2V protein
has been identified in atria of humans with
cardiomyopathy,23 but its expression
has never been reported in rodent atria. The genes that exhibited
altered expression in mutants may be target genes of JMJ. Further
investigation is necessary to determine the direct target genes of
JMJ.
JMJ is a nuclear factor containing a region homologous to the DNA binding domain of the transcription factor family, ARID. The B-cell–specific transactivator Bright24 and the dead ringer gene product25 are members of this multigene family. Therefore, JMJ may be involved in a transcription factor cascade in heart development. The other motif in JMJ is homologous to yeast SWI1, which mediates transcriptional activation,26 and 2 retinoblastoma (Rb) binding proteins.27 Thus, JMJ may also be involved in cell proliferation and differentiation via interaction with the cell cycle regulator pRb or pRb-related factors, such as p107.28 Given that we observed no increase in apoptotic cells in cardiomyocytes from E13 to E17 embryos, the reduced cellularity of the myocardium is likely caused by hypoplasia in mutants. Previously described hypoplasia of the liver, thymus, and spleen in jmj mutants11 supports this hypothesis.
Phenotype Variations in Homozygous jmj
Mutants
Homozygous jmj mice have been previously generated by a
gene trap strategy, which exhibited a neural tube
defect10 or hemorrhage11 29
depending on the genetic background of mutants. There may be several
reasons for the different phenotype in our jmj
mutants compared with previous publications. First, it may be due to a
difference in the genetic background of the mutants. Our jmj
homozygous mice have a heterogeneous genetic background
from 129/Svx129/SvJ R1 ES cells injected into C57BL/6 blastocyst, and
outbred with C57BL/6, that is different from those of previous reports.
This phenomenon of changes in phenotype with different genetic
backgrounds has been described.30 Second, the gene
trap insertion site may cause the differences in phenotype.
Gene alteration in the mouse may disrupt the expression of other genes
located nearby. A very striking case of such neighboring effects
emerged from the targeted inactivation of the myogenic
basic-helix-loop-helix gene MRF4.31
The gene trap vector in this study inserted 5' to the previously
reported vector insertion site in the same intron.10
Third, although the gene trap insertion generates a mutation at the
genomic level, creation of a null mouse line does not appear to occur
in all cases because wild-type transcripts were observed in homozygous
mice.32 33 Our homozygotes were protected from the
reported nervous system defects,10 because the
jmj transcript was expressed in the nervous system of the
mutants. The mechanism of splicing around the gene trap vector in a
nervous system–specific manner in our homozygotes remains unknown.
Retrovirus insertional mutation can affect gene expression in a
tissue-specific manner.34
The cardiac abnormalities in jmj mutant hearts may reflect a
primary deficiency of JMJ in the myocardium. However, given
that JMJ is broadly expressed during gestation, another lineage might
influence maturation and expansion of the myocardium and
also provide positional cues for appropriate cushion and outflow tract
development. For example, the RXR mutant phenotype is not
cell autonomous for the cardiomyocyte lineage, because
ventricular muscle-restricted targeting of RXR reveals a
completely normal phenotype.35
In summary, the present study demonstrates that JMJ is a nuclear factor that plays a critical role in normal heart development and is necessary for survival of newborn mice. Therefore, jmj mutant mice provide valuable information in the understanding of molecular defects in congenital heart disease.
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Acknowledgments |
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G.E.L. is an Established Investigator of the American Heart Association. S.J.C. acknowledges support by NIH grants HL60714 and HL60104 and a Basil O’Connor Award from the March of Dimes.
Received January 10, 2000; accepted February 17, 2000.
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References |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
1. Fishman MC, Olson EN. Parsing the heart: genetic modules for organ assembly. Cell. 1997;91:153–156.[Medline] [Order article via Infotrieve]
2.
Lin Q, Schwarz J, Bucana C, Olson EN. Control of mouse
cardiac morphogenesis and myogenesis by transcription factor MEF2C.
Science. 1997;276:1404–1407.
3.
Kuo CT, Morrisey EE, Anandappa R, Sigrist K, Lu MM,
Parmacek MS, Soudais C, Leiden JM. GATA4 transcription factor is
required for ventral morphogenesis and heart tube formation.
Genes Dev. 1997;11:1048–1060.
4.
Molkentin JD, Lin Q, Duncan SA, Olson EN. Requirement
of the transcription factor GATA4 for heart tube formation and ventral
morphogenesis. Genes Dev. 1997;11:1061–1072.
5.
Lyons I, Parsons LM, Hartley L, Li R, Andrews JE, Robb
L, Harvey RP. Myogenic and morphogenetic defects in the heart tubes of
murine embryos lacking the homeo box gene Nkx2-5. Genes Dev. 1995;9:1654–1666.
6. Lyons GE. Vertebrate heart development. Curr Opin Genet Dev. 1996;6:454–460.[Medline] [Order article via Infotrieve]
7.
Schott JJ, Benson DW, Basson CT, Pease W, Silberbach
GM, Moak JP, Maron BJ, Seidman CE, Seidman JG. Congenital heart disease
caused by mutations in the transcription factor NKX2-5.
Science. 1998;281:108–111.
8.
Yamagishi H, Garg V, Matsuoka R, Thomas T,
Srivastava D. A molecular pathway revealing a genetic basis for human
cardiac and craniofacial defects. Science. 1999;283:1158–1161.
9. Baker RK, Haendel MA, Swanson BJ, Shambaugh JC, Micales BK, Lyons GE. In vitro preselection of gene-trapped embryonic stem cell clones for characterizing novel developmentally regulated genes in the mouse. Dev Biol. 1997;185:201–214.[Medline] [Order article via Infotrieve]
10.
Takeuchi T, Yamazaki Y, Katoh-Fukui Y, Tsuchiya R,
Kondo S, Motoyama J, Higashinakagawa T. Gene trap capture of a novel
mouse gene, jumonji, required for neural tube formation. Genes
Dev. 1995;9:1211–1222.
11. Motoyama J, Kitajima K, Kojima M, Kondo S, Takeuchi T. Organogenesis of the liver, thymus and spleen is affected in jumonji mutant mice. Mech Dev. 1997;66:27–37.[Medline] [Order article via Infotrieve]
12. Takeuchi T, Kojima M, Nakajima K, Kondo S. jumonji gene is essential for the neurulation and cardiac development of mouse embryos with a C3H/He background. Mech Dev. 1999;86:29–38.[Medline] [Order article via Infotrieve]
13. Kaufman MH. Differentiation of the skeletal system. In: The Atlas of Mouse Development. New York, NY: Academic Press; 1992:495–497.
14. Lyons GE. In situ analysis of the cardiac muscle gene program during embryogenesis. Trends Cardiovasc Med. 1994;4:70–77.
15.
Lyons GE, Schiaffino S, Sassoon D, Barton P, Buckingham
M. Developmental regulation of myosin gene expression in mouse cardiac
muscle. J Cell Biol. 1990;111:2427–2436.
16.
Argentin S, Ardati A, Tremblay S, Lihrmann I,
Robitaille L, Drouin J, Nemer M. Developmental stage-specific
regulation of atrial natriuretic factor gene transcription
in cardiac cells. Mol Cell Biol. 1994;14:777–790.
17.
Lee Y, Shioi T, Kasahara H, Jobe SM, Wiese RJ, Markham
BE, Izumo S. The cardiac tissue-restricted homeobox protein Csx/Nkx2.5
physically associates with the zinc finger protein GATA4 and
cooperatively activates atrial natriuretic factor
gene expression. Mol Cell Biol. 1998;18:3120–3129.
18.
Hogers B, DeRuiter MC, Gittenberger-de Groot AC,
Poelmann RE. Unilateral vitelline vein ligation alters intracardiac
blood flow patterns and morphogenesis in the chick embryo. Circ
Res. 1997;80:473–481.
19. Mendelsohn C, Lohnes D, Decimo D, Lufkin T, LeMeur M, Chambon P, Mark M. Function of the retinoic acid receptors (RARs) during development, II: multiple abnormalities at various stages of organogenesis in RAR double mutants. Development. 1994;120:2749–2771.[Abstract]
20.
Sucov HM, Dyson E, Gumeringer CL, Price J, Chien KR,
Evans RM. RXR mutant mice establish a genetic basis for vitamin
A signaling in heart morphogenesis. Genes Dev. 1994;8:1007–1018.
21. Sanford LP, Ormsby I, Gittenberger-de Groot AC, Sariola H, Friedman R, Boivin GP, Cardell EL, Doetschman T. TGFß2 knockout mice have multiple developmental defects that are non-overlapping with other TGF-ß knockout phenotypes. Development. 1997;124:2659–2670.[Abstract]
22.
Lee Y, Nadal-Ginard B, Mahdavi V, Izumo S.
Myocyte-specific enhancer factor 2 and thyroid hormone receptor
associate and synergistically activate the -cardiac
myosin heavy chain gene. Mol Cell Biol. 1997;17:2745–2755.[Abstract]
23. Cummins P. Transitions in human atrial and ventricular myosin light-chain isoenzymes in response to cardiac-pressure-overload-induced hypertrophy. Biochem J. 1982;205:195–204.[Medline] [Order article via Infotrieve]
24.
Herrscher RF, Kaplan MH, Lelsz DL, Das C, Scheuermann
R, Tucker PW. The immunoglobulin heavy-chain matrix-associating regions
are bound by Bright, a B cell-specific trans-activator that
describes a new DNA-binding protein family. Genes Dev. 1995;9:3067–3082.
25. Gregory SL, Kortschak RD, Kalionis B, Saint R. Characterization of the dead ringer gene identifies a novel, highly conserved family of sequence-specific DNA-binding proteins. Mol Cell Biol. 1996;16:792–799.[Abstract]
26. Peterson CL, Herskowitz I. Characterization of the yeast SWI1, SWI2, and SWI3 genes, which encode a global activator of transcription. Cell. 1992;68:573–583.[Medline] [Order article via Infotrieve]
27. Fattaey AR, Helin K, Dembski MS, Dyson N, Harlow E, Vuocolo GA, Hanobik MG, Haskell KM, Oliff A, Defeo-Jones D. Characterization of the retinoblastoma binding proteins RBP1 and RBP2. Oncogene. 1993;8:3149–3156.[Medline] [Order article via Infotrieve]
28.
Zhu L, van den Heuvel S, Helin K, Fattaey A, Ewen M,
Livingston D, Dyson N, Harlow E. Inhibition of cell proliferation by
p107, a relative of the retinoblastoma protein. Genes Dev. 1993;7:1111–1125.
29.
Kitajima K, Kojima M, Nakajima K, Kondo S, Hara T,
Miyajima A, Takeuchi T. Definitive but not primitive hematopoiesis is
impaired in jumonji mutant mice. Blood. 1999;93:87–95.
30.
Sibilia M, Wagner EF. Strain-dependent epithelial
defects in mice lacking the EGF receptor. Science. 1995;269:234–238.
31. Olson EN, Arnold HH, Rigby PW, Wold BJ. Know your neighbors: three phenotypes in null mutants of the myogenic bHLH gene MRF4. Cell. 1996;85:1–4.[Medline] [Order article via Infotrieve]
32. McClive P, Pall G, Newton K, Lee M, Mullins J, Forrester L. Gene trap integrations expressed in the developing heart: insertion site affects splicing of the PT1-ATG vector. Dev Dyn. 1998;212:267–276.[Medline] [Order article via Infotrieve]
33. Voss AK, Thomas T, Gruss P. Efficiency assessment of the gene trap approach. Dev Dyn. 1998;212:171–180.[Medline] [Order article via Infotrieve]
34. Seperack PK, Mercer JA, Strobel MC, Copeland NG, Jenkins NA. Retroviral sequences located within an intron of the dilute gene alter dilute expression in a tissue-specific manner. EMBO J. 1995;14:2326–2332.[Medline] [Order article via Infotrieve]
35.
Chen J, Kubalak SW, Chien KR. Ventricular
muscle-restricted targeting of the RXR gene reveals a
non-cell-autonomous requirement in cardiac chamber morphogenesis.
Development. 1998;125:1943–1949.[Abstract]
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 B. C. Lin, R. Sullivan, Y. Lee, S. Moran, E. Glover, and C. A. Bradfield Deletion of the Aryl Hydrocarbon Receptor-associated Protein 9 Leads to Cardiac Malformation and Embryonic Lethality J. Biol. Chem., December 7, 2007; 282(49): 35924 - 35932. [Abstract] [Full Text] [PDF]
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|
 A. J. Bingham, L. Ooi, L. Kozera, E. White, and I. C. Wood The Repressor Element 1-Silencing Transcription Factor Regulates Heart-Specific Gene Expression Using Multiple Chromatin-Modifying Complexes Mol. Cell. Biol., June 1, 2007; 27(11): 4082 - 4092. [Abstract] [Full Text] [PDF]
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J. Jung, T.-g. Kim, G. E. Lyons, H.-R. C. Kim, and Y. Lee Jumonji Regulates Cardiomyocyte Proliferation via Interaction with Retinoblastoma Protein J. Biol. Chem., September 2, 2005; 280(35): 30916 - 30923. [Abstract] [Full Text] [PDF]
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 A. Patsialou, D. Wilsker, and E. Moran DNA-binding properties of ARID family proteins Nucleic Acids Res., January 7, 2005; 33(1): 66 - 80. [Abstract] [Full Text] [PDF]
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T.-g. Kim, J. Chen, J. Sadoshima, and Y. Lee Jumonji Represses Atrial Natriuretic Factor Gene Expression by Inhibiting Transcriptional Activities of Cardiac Transcription Factors Mol. Cell. Biol., December 1, 2004; 24(23): 10151 - 10160. [Abstract] [Full Text] [PDF]
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T.-G. Kim, J. C. Kraus, J. Chen, and Y. Lee JUMONJI, a Critical Factor for Cardiac Development, Functions as a Transcriptional Repressor J. Biol. Chem., October 24, 2003; 278(43): 42247 - 42255. [Abstract] [Full Text] [PDF]
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 D. L. Brutsaert Cardiac Endothelial-Myocardial Signaling: Its Role in Cardiac Growth, Contractile Performance, and Rhythmicity Physiol Rev, January 1, 2003; 83(1): 59 - 115. [Abstract] [Full Text] [PDF]
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 Y. Sakata, C. N. Kamei, H. Nakagami, R. Bronson, J. K. Liao, and M. T. Chin Ventricular septal defect and cardiomyopathy in mice lacking the transcription factor CHF1/Hey2 PNAS, December 10, 2002; 99(25): 16197 - 16202. [Abstract] [Full Text] [PDF]
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 K. R. Boheler, J. Czyz, D. Tweedie, H.-T. Yang, S. V. Anisimov, and A. M. Wobus Differentiation of Pluripotent Embryonic Stem Cells Into Cardiomyocytes Circ. Res., August 9, 2002; 91(3): 189 - 201. [Abstract] [Full Text] [PDF]
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K. S. Hewitson, L. A. McNeill, M. V. Riordan, Y.-M. Tian, A. N. Bullock, R. W. Welford, J. M. Elkins, N. J. Oldham, S. Bhattacharya, J. M. Gleadle, et al. Hypoxia-inducible Factor (HIF) Asparagine Hydroxylase Is Identical to Factor Inhibiting HIF (FIH) and Is Related to the Cupin Structural Family J. Biol. Chem., July 12, 2002; 277(29): 26351 - 26355. [Abstract] [Full Text] [PDF]
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 D. Wilsker, A. Patsialou, P. B. Dallas, and E. Moran ARID Proteins: A Diverse Family of DNA Binding Proteins Implicated in the Control of Cell Growth, Differentiation, and Development Cell Growth Differ., March 1, 2002; 13(3): 95 - 106. [Abstract] [Full Text] [PDF]
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J. D. Crispino, M. B. Lodish, B. L. Thurberg, S. H. Litovsky, T. Collins, J. D. Molkentin, and S. H. Orkin Proper coronary vascular development and heart morphogenesis depend on interaction of GATA-4 with FOG cofactors Genes & Dev., April 1, 2001; 15(7): 839 - 844. [Abstract] [Full Text]
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K. M. Caron and O. Smithies Extreme hydrops fetalis and cardiovascular abnormalities in mice lacking a functional Adrenomedullin gene PNAS, January 5, 2001; (2001) 21548898. [Abstract] [Full Text]
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D. Srivastava Congenital Heart Defects : Trapping the Genetic Culprits Circ. Res., May 12, 2000; 86(9): 917 - 918. [Full Text] [PDF]
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G. F. Wang, W. Nikovits Jr., Z.-Z. Bao, and F. E. Stockdale Irx4 Forms an Inhibitory Complex with the Vitamin D and Retinoic X Receptors to Regulate Cardiac Chamber-specific slow MyHC3 Expression J. Biol. Chem., July 27, 2001; 276(31): 28835 - 28841. [Abstract] [Full Text] [PDF]
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K. M. Caron and O. Smithies Extreme hydrops fetalis and cardiovascular abnormalities in mice lacking a functional Adrenomedullin gene PNAS, January 16, 2001; 98(2): 615 - 619. [Abstract] [Full Text] [PDF]
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