Jablonski Monica M, Dalke Claudia, Wang XiaoFei, Lu Lu, Manly Kenneth F, Pretsch Walter, Favor Jack, Pardue Machelle T, Rinchik Eugene M, Williams Robert W, Goldowitz Daniel, Graw Jochen
Department of Ophthalmology, University of Tennessee Health Science Center and Tennessee Mouse Genome Consortium, Memphis, TN, USA.
Mol Vis. 2005 Jul 27;11:569-81.
The 44TNJ mutant mouse was generated by the Tennessee Mouse Genome Consortium (TMGC) using an ENU-based mutagenesis screen to produce recessive mutations that affect the eye and brain. Herein we present its retinal phenotype and genetic basis.
Fourth generation offspring (G4) and confirmed mutants were examined using slit lamp biomicroscopy, funduscopy, histology, immunohistochemistry, and electroretinography (ERG). 44TNJ mutant mice were crossed to C3BLiA or DBA/2 mice for chromosomal mapping purposes. Linkage analysis by PCR-based microsatellite marker genotyping was used to identify the disease locus. The Rs1h cDNA and its genomic DNA were sequenced directly.
The 44TNJ pedigree was the first mutant pedigree identified by the ocular phenotyping domain of the TMGC. Examination of the fundus revealed numerous small and homogeneous intraretinal microflecks in the peripapillary region, which became courser and more irregular in the periphery. Males were typically more affected than females. Histology and immunohistochemistry revealed a disruption of the lamination of the retina, particularly at both margins of the outer nuclear layer, along with reduced calbindin immunostaining. ERG analyses revealed reduced amplitudes of both a-waves and b-waves. Linkage analysis mapped the 44TNJ mutation to the X chromosome close to the marker DXMit117. Sequence analysis of the positional candidate gene Rs1h revealed a T->C exchange at the second base of intron 2 of the Rs1h gene.
We have generated and characterized a mutant mouse line that was produced using ENU-based mutagenesis. The 44TNJ pedigree manifests with photoreceptor dysfunction and concurrent structural and functional aberrations at the post-receptoral level. Genetic analysis revealed a mutation in Rs1h, making this the first murine model of X-linked retinoschisis in which the gene is expressed.
44TNJ突变小鼠由田纳西小鼠基因组联盟（TMGC）通过基于ENU的诱变筛选产生，以产生影响眼睛和大脑的隐性突变。在此，我们展示其视网膜表型和遗传基础。
使用裂隙灯生物显微镜检查、眼底镜检查、组织学、免疫组织化学和视网膜电图（ERG）对第四代后代（G4）和已确认的突变体进行检查。为了进行染色体定位，将44TNJ突变小鼠与C3BLiA或DBA/2小鼠杂交。通过基于PCR的微卫星标记基因分型进行连锁分析，以鉴定疾病位点。直接对Rs1h cDNA及其基因组DNA进行测序。
44TNJ家系是TMGC的眼部表型分析领域鉴定出的首个突变家系。眼底检查发现视乳头周围区域有许多小而均匀的视网膜内微斑点，周边区域的微斑点变得更粗大且更不规则。雄性通常比雌性受影响更严重。组织学和免疫组织化学显示视网膜分层破坏，特别是在外核层的两个边缘，同时钙结合蛋白免疫染色减少。ERG分析显示a波和b波的振幅均降低。连锁分析将44TNJ突变定位到靠近标记DXMit117的X染色体上。对定位候选基因Rs1h的序列分析显示，Rs1h基因内含子2的第二个碱基处发生了T->C交换。
我们产生并鉴定了一个使用基于ENU的诱变产生的突变小鼠品系。44TNJ家系表现为光感受器功能障碍以及受体后水平的结构和功能同时出现异常。遗传分析揭示Rs1h存在突变，使其成为首个该基因表达的X连锁视网膜劈裂症小鼠模型。
