An ENU-induced mutation in Rs1h causes disruption of retinal structure and function

Department of Ophthalmology, Emory University, Atlanta, Georgia, United States
Molecular vision (Impact Factor: 1.99). 07/2005; 11(67):569-81.
Source: PubMed


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.

Download full-text


Available from: Monica M Jablonski
  • Source
    • "The fundi were examined with indirect ophthalmoscopy. Photographs were taken using a Kowa Genesis (Torrance, CA) small animal fundus camera equipped with a 90 D condensing lens (Volk, Mentor, OH) [27], and 160T slide film (Kodak, Rochester, NY) was used for photographic documentation. One of the authors (XFW) provided written descriptions of the ocular findings; subsequently, the eyes were scored as having a low, medium, or high degree of disease independently of knowledge of the mouse genotype or pathology findings. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Persistent hyperplastic primary vitreous (PHPV) represents a developmental eye disease known to have diverse manifestations ranging from a trivial remnant of hyaloid vessels to a dense fibrovascular mass causing lens opacity and retinal detachment. PHPV can be modeled in mice lacking individual genes, but certain features of such models differ from the clinical realm. For example, mice lacking the Arf gene have uniformly severe disease with consistent autosomal recessive disease penetrance. We tested whether the graded somatic loss of Arf in a subset of cells in chimeric mice mimics the range of disease in a non-heritable manner. Wild type ↔ Arf (-/-) mouse chimeras were generated by morulae fusion, and when the mice were 10 weeks old, fundoscopic, slit-lamp, and histological evaluations were performed. The relative fraction of cells of the Arf (-/-) lineage was assessed with visual, molecular genetic, and histological analysis. Objective quantification of various aspects of the phenotype was correlated with the genotype. Sixteen chimeras were generated and shown to have low, medium, and high contributions of Arf (-/-) cells to tail DNA, the cornea, and the retinal pigment epithelium (RPE), with excellent correlation between chimerism in the tail DNA and the RPE. Phenotypic differences (coat color and severity of eye disease) were evident, objectively quantified, and found to correlate with the contribution of Arf (-/-) cells to the RPE and tail-derived DNA, but not the cornea. Generating animals composed of different numbers of Arf (-/-) cells mimicked the range of disease severity observed in patients with PHPV. This establishes the potential for full manifestations of PHPV to be caused by somatic mutations of a single gene during development.
    Full-text · Article · Mar 2014 · Molecular vision
  • Source
    • "Knockout mouse models have been helpful in deducing the molecular mechanisms of the retinal degeneration and in evaluating the strategies for gene therapy. The RS1 knockout mice share several important clinical features with human XLRS disease (Weber et al. 2002; Zeng et al. 2004; Jablonski et al. 2005; Kjellstrom et al. 2007). Consistent with a role for RS1 in maintaining photoreceptor stability, electron microscopy showed profound pathological alterations in the morphology of rod inner segments in the absence of RS1 protein (Johnson et al. 2006; Takada et al. 2008). "
    [Show abstract] [Hide abstract]
    ABSTRACT: There is good evidence that retinoschisin (RS1) is one of the key participants in retinal cell adhesion processes controlling the formation of retinal cell layers and mosaics. Loss-of-function mutations in the X-linked retinoschisis (RS1) gene lead to splitting within the retina, a condition known as the X-linked juvenile retinoschisis (XLRS). XLRS causes impairment of visual activity in young males and frequently progresses to even more severe reduction of both central and peripheral vision with age. This perspective reviews progress in the field of RS1 biology and pathophysiology.
    Full-text · Article · Jan 2012 · Advances in Experimental Medicine and Biology
  • Source
    • "They also demonstrated displacement of cells from the photoreceptor outer nuclear layer (ONL) and reduced thickness of the outer segment layer (Zeng et al., 2004). More recently, a third mouse model was generated using an ENU mutagenesis approach (Jablonski et al., 2005) derived from an induced mutation in intron 2 of RS1h, which leads to two novel splice variants. It is remarkable that, similar to the human condition, male homozygous mutant mice have retinal abnormalities as early as two weeks of age which do not appear to progress up to 38 weeks. "

    Full-text · Chapter · Aug 2011
Show more