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Phenotypes Associated with This Genotype
Genotype
MGI:3038279
Allelic
Composition
Rxratm4Ipc/Rxratm4Ipc
Tg(Tyrp1-cre)1Ipc/0
Genetic
Background
involves: 129S2/SvPas
Find Mice Using the International Mouse Strain Resource (IMSR)
Mouse lines carrying:
Rxratm4Ipc mutation (0 available); any Rxra mutation (30 available)
Tg(Tyrp1-cre)1Ipc mutation (0 available)
phenotype observed in females
phenotype observed in males
N normal phenotype
vision/eye
• presence of large and irregular intercellular spaces between the photoreceptor outer segments
• large cysts and ectopic RPE cells are frequently seen in the photoreceptor outer segment layer of the retina
• alteration of the outer segment disk membranes
• photoreceptor outer segments are 77%, 66% and 65% shorter at 3, 12, and 18 months of age, respectively
• photoreceptor outer segments appear disorganized beginning at 1 month of age and onwards
• retinal pigment epithelium (RPE) cells at 3 months of age are abnormally flat and elongated and often overlap with one another
• RPE cells have poorly developed apical microvilli and basal membrane infoldings and fewer phagosomes
• RPE cells have abnormal organelles such as large phagolysosomes and vacuoles and numerous lipid droplets
• cytoplasmic fragments, large cysts and myeloid bodies are seen on the apical side of the RPE
• RPE exhibits an uneven distribution of melanin granules at P12 and fewer melanin granules within RPE cells
• melanin granule shape is irregular and typical fusiform granules are almost lacking
• thickness of entire retinal pigment epithelium (RPE) is decreased at P12, and 3, 12, and 18 months of age, but not at E17.5 or P4
• number of nuclear rows in the outer nuclear layer is 83%, 80% and 78% of controls at 3, 12, and 19 months of age, respectively
• b-wave amplitudes in both flicker and photopic electroretinograms (ERGs) are reduced by about 50%, however no differences in the latency of b-waves
• both a- and b-wave amplitudes are reduced by about 50% indicating reduced scotopic responses, however no differences in the latency of for the a- and b-waves
• delay in dark adaptation after photo bleach

pigmentation
• retinal pigment epithelium (RPE) cells at 3 months of age are abnormally flat and elongated and often overlap with one another
• RPE cells have poorly developed apical microvilli and basal membrane infoldings and fewer phagosomes
• RPE cells have abnormal organelles such as large phagolysosomes and vacuoles and numerous lipid droplets
• cytoplasmic fragments, large cysts and myeloid bodies are seen on the apical side of the RPE
• RPE exhibits an uneven distribution of melanin granules at P12 and fewer melanin granules within RPE cells
• melanin granule shape is irregular and typical fusiform granules are almost lacking
• thickness of entire retinal pigment epithelium (RPE) is decreased at P12, and 3, 12, and 18 months of age, but not at E17.5 or P4

nervous system
• presence of large and irregular intercellular spaces between the photoreceptor outer segments
• large cysts and ectopic RPE cells are frequently seen in the photoreceptor outer segment layer of the retina
• alteration of the outer segment disk membranes
• photoreceptor outer segments are 77%, 66% and 65% shorter at 3, 12, and 18 months of age, respectively
• photoreceptor outer segments appear disorganized beginning at 1 month of age and onwards


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)
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last database update
03/18/2025
MGI 6.24
The Jackson Laboratory