The semidominant lens opacity 20 (Lop20) mutation in gamma crystallin c causes small eyes, with homozygotes having eyes that are only 30 to 50% the size of wildtype and heterozygotes having eyes that are approximately 75% the size of wildtype. Both homozygotes and heterozygotes develop cataracts that are evident by 1 month of age with dense nuclear opacification with irregular edges at the junction between the nucleus and cortex, and the cortex subsequently becomes cloudy.
The lens opacity 20 (Lop20) mutation was identified in an F1 hybrid mouse from a cross of BALB/cJ x A/J. This semidominant mutation was backcrossed at least once to BALB/cJ then the strain was maintained by sibling intercrossing and eventually maintained homozygous for Lop20. Sperm was cryopreserved from homozygous males at generation F20.
|Allele Name||lens opacity 20|
|Allele Type||Spontaneous (Hypomorph)|
|Gene Symbol and Name||Crygc, crystallin, gamma C|
|Strain of Origin||(BALB/cJ x A/J)F1|
|Molecular Note||This spontaneous 2 base pair insertion (GC) in exon 3 causes a frameshift after codon 124 and premature stop at codon 147.|