Affected mice have white or opaque lenses, may have a belly spot, and may have caudal spina bifida. Although the lens defect is the most. consistent landmark of this mutant, occasionally homozygotes have only a belly spot. Histological study of the lens shows that at birth there are small vacuoles in the lens. The spina bifida is apparent in all embryos at 11 to 12 days of gestation, but is visible in only about 1/3 to 1/2 the affected animals at birth. If this defect is not too severe, the lesion heals and the animal survives.
Vacuolated lens arose spontaneously in 1964 in the C3HeB/FeJ strain at The Jackson Laboratory. It was backcrossed once to C3HeB/FeJ and then sibling intercrossed for three generations before being outcrossed to C3H/HeSnJ and then maintained by sibling breeding for many years. In 1988 embryos were cryopreserved from homozygous females at generation F82 bred with heterozygous males at generation F76.
|Allele Name||vacuolated lens|
|Gene Symbol and Name||Gpr161, G protein-coupled receptor 161|
|Strain of Origin||C3HeB/FeJ|
|Molecular Note||The molecular lesion is an 8-bp deletion in exon 4. This mutation is expected to cause a frameshift and premature stop codon 50 nt 3' of the deletion that results in the incorporation of 16 novel amino acids (GAHGRRTVPGTQQQHR) and truncation of the GPCR at residue 386, deleting 143 (of 203) amino acids of the C-terminal tail. An in vitro assay showed that a smaller protein can be expressed from a construct carrying this mutation and assay results suggest that internalization of the protein from the plasma membrane into the endosomal compartment is disrupted by this mutation.|