A new hereditary cataract mouse with lens rupture and mapping of the cataract gene

一种新的白内障模型起源于BALB/cHeA（BALB/c或C）和STS/A（STS或S）小鼠之间的重组近交（RI）品系CXS 4或CXSD（D）。从5周龄开始，白化病小鼠的无色素眼睛中出现不透明的白色针尖状病灶。所有小鼠在14周龄时双侧受累。它们是完全可行的和肥沃的。白内障发病率无性别差异。在组织学上，3-4月龄的小鼠在透镜皮质中显示空泡。晚期病例的空泡遍布透镜皮质。透镜核破裂至玻璃体腔是一种典型的情况。为了阐明遗传模式，分析了F1杂种（CXD和SXD）和回交后代[（CXD）F1 XD和（SXD）F1 XD]。在F1代杂种中未观察到受影响的小鼠。在回交后代中，患鼠与正常鼠的分离比在两次交配中都接近1：1。结论：白内障为常染色体单隐性基因遗传。该突变基因暂时命名为“透镜破裂2”（基因符号1 r2，小鼠基因组数据库登录号MGD-JNUM-37399）。为了进行连锁分析，我们产生了两种回交后代，（BALB/cHeA × D）F1和（STS/A × D）F1雌性与D雄性杂交。该基因（lr 2，透镜破裂2）定位于第14号染色体的中部，距离微卫星标记D14 Mit 28为0.7 +/-0.7cM。

A new cataract model originated in a recombinant inbred (RI) strain, CXS4 or CXSD (D), between BALB/cHeA (BALB/c or C) and STS/A (STS or S) mice. Opacity appeared as a white pinpoint focus in unpigmented eyes of albino mice from 5 weeks old. All the mice were bilaterally affected by 14 weeks old. They were fully viable and fertile. There was no sex difference in incidence of cataract. Histologically, the 3-4 months old mice showed vacuoles in the lens cortex. The vacuoles were spread all over the lens cortex in advanced cases. Ruptures of the lens nucleus to the vitreous chamber was a typical occurrence. For elucidation of the mode of inheritance, F1 hybrids (CXD and SXD) and backcross progenies [(CXD) F1XD and (SXD) F1XD] were analyzed. NO affected mice were observed in F1 hybrids. In backcross progenies, the segregation ratio of affected and normal mice was close to 1 : 1 in both matings. We conclude that the cataract is inherited by an autosomal single recessive gene. This mutant gene is provisionally named 'lens rupture 2' (gene symbol 1r2, Mouse Genome Database Accession No.MGD-JNUM-37399).Mapping of the spontaneous autosomal recessive cataract mutant gene was performed. For the linkage analysis, we produced two kinds of backcross progenies, (BALB/cHeA x D) F1 and (STS/A x D) F1 females crossed to D male mice. The gene (lr2, lens rupture2) was mapped to the central part of Chromosome (Chr) 14,0.7+/-0.7 cM from the micosatellite marker D14Mit28.