Vldlrrnv4 homozygotes have been reported to provide a more consistent and robust retinal angiogenesis phenotype than that found in Vldlrtm1Her homozygotes). Blood vessels have been observed in the subretinal space as early as 14 days of age. The aberrant retinal vascularization is evident by indirect ophthalmoscopy as pink-grey retinal lesions. The dark-adapted ERG amplitude readings are decreased at 1 month and continue to diminish with age, and by 1 month of age the light-adapted ERG response is delayed compared to controls.
This A to G transition next to a single base pair (A) deletion in exon 12, which is predicted to cause a frameshift and premature stop codon at amino acid 540, arose spontaneously in the C57BLKS/J-Npc1spm strain. The pink-grey retinal lesions phenotype was identified in a screen in the laboratory of Dr. Bo Chang at The Jackson Laboratory in 2007 and was segregating in that strain at that time. An rnv4 homozygous mutant that was wildtype for the Npc1spm phenotype was bred to a C57BL/6J male, their offspring were sibling intercrossed and the line was maintained by sibling inbreeding reaching generation N1F23 in early 2019.
|Allele Name||retinal neovascularization 4|
|Allele Type||Spontaneous (Not Specified)|
|Gene Symbol and Name||Vldlr, very low density lipoprotein receptor|
|Strain of Origin||C57BLKS/J-Npc1spm/J|
|Molecular Note||This spontaneous A to G transition next to a single base pair (A) deletion in exon 12 results in a frameshift and premature stop codon at amino acid 540.|