A mutation in the connexin 50 (Cx50) gene is a candidate for the No2 mouse cataract.
A mutation in the connexin 50 (Cx50) gene is a candidate for the No2 mouse cataract.
复制标题
连接蛋白 50 (Cx50) 基因的突变是 No2 小鼠白内障的候选者。
DOI：
10.1076/ceyr.17.9.883.5144
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发表时间：
1998
影响因子：
2
通讯作者：
Church,RL
中科院分区：
文献类型：
--
作者：
SteeleJr,EC;Lyon,MF;Favor,J;Guillot,PV;Boyd,Y;Church,RL
第2号白内障小鼠突变体表现出双侧先天性遗传性眼透镜核混浊。这项工作的目的是确定并随后筛选一个最佳的候选基因的突变相关和一致的观察phenotype. METHODS的No2白内障的基因和微卫星标记进行了映射，通过杂交野生小鼠品系小鼠spretus，然后回交的近交系C3 H/ HeH。从正常亲本以及杂合和纯合突变体基因组DNA中扩增Cx 50（MP 70）蛋白编码区和侧翼序列。这些PCR产物直接测序。PCR产物的限制性内切酶分析证实了序列数据的正确性，对2号白内障的RT-PCR图谱将其定位在Gja 8基因附近，Gja 8基因编码连接蛋白50（MP 70），该连接蛋白50是透镜纤维间隙连接的主要成分。Cx 50蛋白编码区的扩增和随后的测序显示一个单一的A？密码子47内的C颠换。该序列变化导致HhaI限制性内切酶限制性位点的产生，允许通过使用该酶的限制性分析确证序列数据。序列的改变也被预测导致丙氨酸（Ala）的非保守性取代的正常编码的天冬氨酸（Asp）在这个位置内的polypeptide.CONCLUSIONSThe确定的突变Gja 8是相关的和一致的白内障中观察到的2号小鼠突变体，使其成为一个理想的候选人白内障。这项研究提供了第一个证据表明，突变的透镜连接蛋白可以导致先天性遗传性白内障，突出了透镜连接蛋白在维持透镜透明度的重要性。
PURPOSEThe No2 cataractous mouse mutant displays a bilateral, congenital, hereditary nuclear opacity of the ocular lens. The aim of this work was to identify and subsequently screen an optimal candidate gene for a mutation correlated and consistent with the observed phenotype.METHODSThe No2 cataract was mapped in relation to genes and microsatellite markers by crossing to the wild mouse strain Mus spretus and then backcrossing to the inbred strain C3H/ HeH. The Cx50 (MP70) protein coding region and flanking sequences were amplified from normal parental as well as heterozygous and homozygous mutant genomic DNAs. These PCR products were then sequenced directly. Sequence data was corroborated by restriction analysis of PCR products.RESULTSMapping of the No2 cataract placed it in the vicinity of Gja8, the gene encoding connexin 50 (MP70), a major component of lens fiber gap junctions. Amplification and subsequent sequencing of the Cx50 protein coding regions revealed a single A ? C transversion within codon 47. This sequence change resulted in the creation of an HhaI restriction endonuclease restriction site, allowing for corroboration of the sequence data via restriction analysis using this enzyme. The sequence alteration is also predicted to result in the nonconservative substitution of alanine (Ala) for the normally encoded aspartic acid (Asp) at this position within the polypeptide.CONCLUSIONSThe identified mutation in Gja8 is both correlated and consistent with the cataract observed in the No2 mouse mutant, making it an ideal candidate for the cataract. This study provides the first evidence that a mutation in a lens connexin can result in congenital hereditary cataract, highlighting the importance of lens connexins in maintaining lens transparency.