Graw J, Bors W, Gopinath P M, Merkle S, Michel C, Reitmeir P, Schäffer E, Summer K H, Wulff A
GSF-Institut für Säugetiergenetik, Neuherberg, Federal Republic of Germany.
Invest Ophthalmol Vis Sci. 1990 Jul;31(7):1353-61.
A dominant cataract mutation was detected recently among the offspring of x-ray-irradiated male mice. The mutation, which causes total lens opacity, has provisionally been designated by the gene symbol Cat-2t. In the lenses of heterozygous and homozygous Cat-2t mutants, the epithelial and fiber cells were swollen and the lens capsule was ruptured. The histologic analysis demonstrated a complete destruction of the cellular organization of the lens, which might be caused by its altered developmental processes. The data derived from biochemical investigations indicate that biochemistry of the cataractous Cat-2t lenses is affected: the osmotic state as indicated by the increased water content and increased Na(+)-K(+)-adenosinetriphosphatase (ATPase) activity; the energy state as indicated by the decreased adenosine triphosphate (ATP) concentration; and the redox state as indicated by the enhanced content of oxidized glutathione. Additionally, the lenticular protein composition is altered because of the presence of vimentin in the water-soluble fraction. This cannot be explained by the enhanced crosslinking activity of transglutaminase. The changes of the osmotic, energy, and redox states are considered to be secondary in relation to the altered lenticular development. In contrast, the variations concerning vimentin and transglutaminase might be a biochemical indication of the changed development. Possible similarities to other dominantly expressed murine cataract mutants are discussed.
最近在经X射线照射的雄性小鼠的后代中检测到一种显性白内障突变。这种导致晶状体完全混浊的突变，暂时被指定为基因符号Cat-2t。在杂合和纯合Cat-2t突变体的晶状体中，上皮细胞和纤维细胞肿胀，晶状体囊破裂。组织学分析表明晶状体的细胞组织完全被破坏，这可能是由其发育过程改变所致。生化研究数据表明，白内障性Cat-2t晶状体的生物化学受到影响：含水量增加和钠钾腺苷三磷酸酶（ATP酶）活性增加表明渗透压状态；三磷酸腺苷（ATP）浓度降低表明能量状态；氧化型谷胱甘肽含量增加表明氧化还原状态。此外，由于波形蛋白存在于水溶性部分，晶状体蛋白组成发生改变。这不能用转谷氨酰胺酶交联活性增强来解释。渗透压、能量和氧化还原状态的变化被认为是晶状体发育改变的继发结果。相比之下，波形蛋白和转谷氨酰胺酶的变化可能是发育改变的生化指标。文中还讨论了与其他显性表达的小鼠白内障突变体可能存在的相似性。
