This strain, which is homozygous for both of Crb1rd8 and Jak3m1J, has a more severe phenotype than Crb1rd8 homozygotes lacking the Jak3m1J mutation, with early-onset multifocal depigmented retinal lesions and photoreceptor loss. The phenotype of the combined genotype provides the model retinal vascularization 3 (rnv3).Read More +
|Allele Type||Gene Symbol||Gene Name|
|Spontaneous||Crb1||crumbs family member 1, photoreceptor morphogenesis associated|
|Allele Type||Gene Symbol||Gene Name|
|Spontaneous (Not Specified)||Jak3||Janus kinase 3|
The ocular phenotype of Crb1rd8 homozygotes is increased in severity by the additional homozygosity of Jak3m1J. Double homozygotes develop multifocal depigmented retinal lesions by 18 days of age which expand in size and by 25 days of age fluorescein leakage is also found. This increases with age and is associated with progressive photoreceptor degeneration and accompanying deterioration of electroretinogram responses. At 8 weeks of age both scotopic and photopic electroretinogram responses are slightly reduced and by 8 months of age this reduction is severe. Neovessels extend from the deep retinal vascular plexus in the outer plexiform layer through the outer retina between 17 and 25 days of age and balloon-like neovessel structures are found in the photreceptor cell layer. By 2 months aberrant vessels are found to span from the retinal pigment epithelium to the inner nuclear layer, the outer nuclear layer is thinner than normal, and photoreceptor cell degeneration occurs where this vasculature disrupts the retina. In addition to the ocular phenotype these double homozygotes have small thymi and spleens due to homozygosity of the Jak3m1J mutation and can develop pneumocystis and die by 6 months of age. Sublines were bred from this strain that have only the Crb1rd8 mutation (see Stock # 031586) or only the Jak3m1J mutation (see Stock # 031587).
Fundus retinal depigmentation spots were identified in the strain B6;129-Crhr1tm1Klee/J. These mice were backcrossed once to C57BL/6J and the resulting F1 hybrids intercrossed. From that population mice lacking the Crhr1tm1Klee mutation but expressing the retinal depigmentation spots were selected and this ocular phenotype was moved onto the C57BL/6J background by repeated rounds of backcross-intercross breeding until NE5 when the strain was intercrossed for homozygosity of both Crb1rd8 and Jak3m1J and maintained by sibling intercrossing.
|Allele Name||retinal degeneration 8|
|Allele Synonym(s)||Crb16N; nmf144; Rd8-|
|Gene Symbol and Name||Crb1, crumbs family member 1, photoreceptor morphogenesis associated|
|Strain of Origin||C57BL/6By or C57BL/6N|
|Molecular Note||The mutation in the rd8 mouse has been identified as a single base deletion of a C (G on forward strand) at coding nucleotide 3481 in the gene. This deletion causes a frame shift and a premature stop codon that truncates the transmembrane and cytoplasmic domain of the protein after amino acid 1207. This mutation has been found to be present in all sublines of C57BL/6N and in C57BL/6ByJ, but not in any C57BL/6J subline. It occurred sometime between transfer of mice from JAX to NIH, in 1951, and from NIH to Donald Bailey, in 1961.|
|Allele Name||mutation 1, Jackson|
|Allele Type||Spontaneous (Not Specified)|
|Gene Symbol and Name||Jak3, Janus kinase 3|
|Strain of Origin||B6;129-Crhr1tm1Klee/J|
|Molecular Note||This spontaneous G to A transition in exon 24 results in a missense mutation, changing codon 1081 from CGG, arginine, to CAG, glutamine. This occurred in a gene sequence already containing the A to C transversion in codon 1032 common in at least 27 inbred strains, which causes an amino acid change from serine to arginine.|
Because Jak3m1J homozygotes are immunocompromised, due consideration should be given to their environment and treatment.
When using the retinal vascularization 3 model
mouse strain in a publication, please cite the originating article(s) and include JAX stock #005558 in your Materials and Methods section.