About   Help   FAQ
Phenotypes associated with this allele
Allele Symbol
Allele Name
Allele ID
Rxratm1Rev
targeted mutation 1, Ronald M Evans
MGI:1857672
Summary 2 genotypes
Jump to Allelic Composition Genetic Background Genotype ID
hm1
Rxratm1Rev/Rxratm1Rev involves: 129S4/SvJae * C57BL/6 MGI:2176443
ht2
Rxratm1Rev/Rxra+ involves: 129S4/SvJae * C57BL/6 MGI:2176444


Genotype
MGI:2176443
hm1
Allelic
Composition
Rxratm1Rev/Rxratm1Rev
Genetic
Background
involves: 129S4/SvJae * C57BL/6
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Rxratm1Rev mutation (1 available); any Rxra mutation (30 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
mortality/aging
• homozygotes die between E13.5 and E16.5, with most embryos still viable at E14.5 but dead by E15.5

cardiovascular system
• at E14.5, only 1 of 10 homozygotes displays an abnormal aortic pulmonary septum; both aortic and pulmonary valves appear unaffected
• at E13.5, upon color fluorescent imaging, the mutant heart appears much more translucent than the wild-type heart
• 28% show incomplete aorticopulmonary septum/aorticopulmonary window
• all homozygotes display impaired differentiation or maturation of the ventricular cardiac myocytes (J:18047)
• spongy layer of the myocardium is generally thicker (J:35363)
• 67% show attenuated trabeculae and contain an unusual, random branching pattern
• by E14.5, ventricular trabeculation is present but reduced and appears disorganized at the muscular septum
• by E14.5, homozygotes show absence of myocyte proliferation at the ventricular epicardial surface ("compact layer")
• 94% exhibit a hypoplastic compact zone of the ventricular myocardium
• 56% exhibit dysmorphic papillary muscles
• 100% have abnormalities of conotruncal ridges ranging from mild deficiency of conotruncal tissue (6%) to complete absence of cushion tissue (66%)
• seen in 11% of homozygotes
• exhibit a wide spectrum of atrioventricular cushion defects
• 67% show partial fusion of the atrioventricular cushions
• complete lack of fusion of the superior and inferior atroioventricular cushions
• portion of embryos with shortened conotruncal ridges exhibit double outlet right ventricle (17%)
• 17% show cleft mitral valve
• by E14.4, 1 of 10 homozygotes displays mitral atresia
• no tricuspid atresia is observed
• 17% show cleft tricuspid valve
• at E14.5, homozygotes exhibit normal atrial structure and function with no differences in overall position of heart and major vessels; however, the left atrium appears small
• at E14.5, 5 of 10 homozygotes display dilation of the right atrial chambers
• 39% show a common atrioventricular canal
• at E14.5, homozygotes display a poorly developed ventricular septum (J:18047)
• by E14.5, 9 of 10 homozygotes display obvious ventricular septal defects at the septal-cushion fusion (J:18047)
• 94% exhibit a ventricular septal defect, with all defects being muscular (J:35363)
• at E11.5 or later, homozygotes exhibit an uneven ventricular contour (J:18047)
• at E14.5, both ventricles exhibit a globular rather than elliptical shape, suggesting a dilated form of congestive heart failure (J:65904)
• by E14.5, all (10 of 10) homozygotes show ventricular chamber hypoplasia
• at E14.5, all (10 of 10) homozygotes exhibit a thinned ventricular wall (J:18047)
• at E13.5, the relatively thin-walled "atrial-like" phenotype of mutant ventricular muscle cells is shown to correlate with the aberrant, persistent expression of an atrial marker (J:18047)
• at E14.5, some homozygotes display dilated right ventricles
• by E14.5, most homozygotes show a prominent pericardial space
• at E11.5 and E12.5, homozygotes exhibit a loosely apposed pericardium; however, the pericardium appears relatively normal at E14.5
• at E13.5 and E14.5, left ventricular area ejection fractions of mutant hearts average 14% vs 50% in wild-type hearts, indicating ventricular dysfunction
• at E14.5, depressed ejection fraction is related to thinned left ventricular wall and impaired shortening of the mutant myocardium
• at E13.5, homozygotes show normal AV synchrony and display heart rates comparable to those of wild-type mice; however, mutant heart rates are slightly decreased at E14.5
• at E14.5, 2 of 10 homozygotes display a complete heart block
• by E14.5, homozygotes with slightly reduced heart rates exhibit an intermittent partial AV block (not quantified)
• homozygotes appear to die in utero as a result of congestive heart failure (J:18047)

homeostasis/metabolism
• at E14.5, homozygotes display a dramatic subdermal edema, that is most prominent along the back and in the folds of skin around the eye
• however, most major organ systems, including the intestine, skin, kidney and eye, appear normal

liver/biliary system
• at E12.5, homozygotes exhibit a marked reduction in hepatocyte proliferation with substantial recovery to ~60% of wild-type values noted at E14.5
• at E12.5, homozygotes display a liver mass that is ~30% of wild-type mice in the absence of morphological defects

muscle
• all homozygotes display impaired differentiation or maturation of the ventricular cardiac myocytes (J:18047)
• spongy layer of the myocardium is generally thicker (J:35363)
• 67% show attenuated trabeculae and contain an unusual, random branching pattern
• by E14.5, ventricular trabeculation is present but reduced and appears disorganized at the muscular septum
• by E14.5, homozygotes show absence of myocyte proliferation at the ventricular epicardial surface ("compact layer")
• 94% exhibit a hypoplastic compact zone of the ventricular myocardium
• 56% exhibit dysmorphic papillary muscles
• at E13.5 and E14.5, left ventricular area ejection fractions of mutant hearts average 14% vs 50% in wild-type hearts, indicating ventricular dysfunction
• at E14.5, depressed ejection fraction is related to thinned left ventricular wall and impaired shortening of the mutant myocardium

integument
• at E14.5, homozygotes display a dramatic subdermal edema, that is most prominent along the back and in the folds of skin around the eye
• however, most major organ systems, including the intestine, skin, kidney and eye, appear normal

cellular
• at E12.5, homozygotes exhibit a marked reduction in hepatocyte proliferation with substantial recovery to ~60% of wild-type values noted at E14.5




Genotype
MGI:2176444
ht2
Allelic
Composition
Rxratm1Rev/Rxra+
Genetic
Background
involves: 129S4/SvJae * C57BL/6
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Rxratm1Rev mutation (1 available); any Rxra mutation (30 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
cardiovascular system
• one heterozygote shows pulmonary artery stenosis
• 49% show trabecular defects with less organized trabecular arrangement
• intermediate thickness of compact layer compared to homozygotes and wild-type, especially prominent at E13.5 and 14.5
• 15% exhibit conotruncal defects, with severity ranging from absent conotruncal ridges (3%) to a shortened conotruncal septum (7%)
• seen in 5% of heterozygotes
• atrioventricular cushion defects range from absent fusion (3%) and hypoplasia (8%) to abnormalities of mature valvular structures
• 17% show cleft mitral valve
• 2% show mitral valve stenosis
• 8% show tricuspid valve abnormalities
• 86% show papillary muscle defects
• severe thinning of the ventricular wall is seen in both the left (2%) and right (2%) ventricles, but never simultaneously
• thin left ventricle wall is associated with mitral valve stenosis yet a normal right ventricle and semilunar va
• thin right ventricle is associated with dysmorphic tricuspid valve yet normal left-sided and semilunar structures

muscle
• 49% show trabecular defects with less organized trabecular arrangement
• intermediate thickness of compact layer compared to homozygotes and wild-type, especially prominent at E13.5 and 14.5
• 86% show papillary muscle defects

Mouse Models of Human Disease
DO ID OMIM ID(s) Ref(s)
congenital heart disease DOID:1682 J:35363





Contributing Projects:
Mouse Genome Database (MGD), Gene Expression Database (GXD), Mouse Models of Human Cancer database (MMHCdb) (formerly Mouse Tumor Biology (MTB)), Gene Ontology (GO)
Citing These Resources
Funding Information
Warranty Disclaimer, Privacy Notice, Licensing, & Copyright
Send questions and comments to User Support.
last database update
04/09/2024
MGI 6.23
The Jackson Laboratory