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

在BALB/cHeA （BALB/c或c）和STS/A （STS或S）小鼠之间建立了一种新的白内障模型，该模型来源于重组自交系（RI） CXS4或CXSD (D)。5周龄时，白化病小鼠无色素眼内可见白色针状病灶。所有小鼠在14周龄时均受到双侧影响。它们完全可以生存和繁殖。白内障的发生率无性别差异。组织学上，3 ~ 4月龄小鼠晶状体皮层可见空泡。在晚期病例中，液泡遍布晶状体皮层。晶状体核破裂到玻璃体腔是典型的。为了阐明遗传模式，对F1杂交后代（CXD和SXD）和回交后代[(CXD) F1XD和（SXD） F1XD]进行了分析。F1杂交种未见染病小鼠。在回交后代中，两次交配中患病小鼠与正常小鼠的分离比接近1:1。我们认为白内障是由常染色体单隐性基因遗传的。该突变基因暂时命名为“晶状体破裂2”（基因符号1r2，小鼠基因组数据库登录号：mgd - jnum -37399）。进行自发性常染色体隐性白内障突变基因的定位。为了进行连锁分析，我们制作了两种回交后代，（BALB/cHeA x D） F1和（STS/A x D） F1雌性与D雄性小鼠杂交。该基因（lr2, lens rupture2）定位于距微卫星标记D14Mit28 0.7+/-0.7 cM的染色体（Chr） 14的中心部分。

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.