title: Deficiency of the RNA binding protein caprin2 causes lens defects and features of Peters anomaly.
abstract: BACKGROUND
  It was recently demonstrated that deficiency of a conserved RNA binding protein (RBP) and RNA granule (RG) component Tdrd7 causes ocular defects including cataracts in human, mouse and chicken, indicating the importance of posttranscriptional regulation in eye development. Here we investigated the function of a second conserved RBP/RG component Caprin2 that is identified by the eye gene discovery tool iSyTE.
  
  
  RESULTS
  In situ hybridization, Western blotting and immunostaining confirmed highly enriched expression of Caprin2 mRNA and protein in mouse embryonic and postnatal lens. To gain insight into its function, lens-specific Caprin2 conditional knockout (cKO) mouse mutants were generated using a lens-Cre deleter line Pax6GFPCre. Phenotypic analysis of Caprin2(cKO/cKO) mutants revealed distinct eye defects at variable penetrance. Wheat germ agglutinin staining and scanning electron microscopy demonstrated that Caprin2(cKO/cKO) mutants have an abnormally compact lens nucleus, which is the core of the lens comprised of centrally located terminally differentiated fiber cells. Additionally, Caprin2(cKO/cKO) mutants also exhibited at 8% penetrance a developmental defect that resembles a human condition called Peters anomaly, wherein the lens and the cornea remain attached by a persistent stalk.
  
  
  CONCLUSIONS
  These data suggest that a conserved RBP Caprin2 functions in distinct morphological events in mammalian eye development.
authors.affiliation: Department of Biological Sciences, University of Delaware, Newark, Delaware.
authors.forename: Soma
authors.initials: S
authors.lastname: Dash
authors.affiliation: Department of Biological Sciences, University of Delaware, Newark, Delaware.
authors.forename: Christine A
authors.initials: CA
authors.lastname: Dang
authors.affiliation: Department of Ophthalmology and Visual Sciences, Washington University, St. Louis, Missouri.
authors.forename: David C
authors.initials: DC
authors.lastname: Beebe
authors.affiliation: Department of Biological Sciences, University of Delaware, Newark, Delaware.|Center for Bioinformatics & Computational Biology, University of Delaware, Newark, Delaware.
authors.forename: Salil A
authors.initials: SA
authors.lastname: Lachke
mesh_terms: D000818:Animals; D000869:Anterior Eye Segment / Q000002:abnormalities*; D018797:Cell Cycle Proteins / Q000378:metabolism; D003318:Corneal Opacity / Q000209:etiology*; D005124:Eye Abnormalities / Q000209:etiology*; D007908:Lens, Crystalline / Q000196:embryology* / Q000378:metabolism / Q000648:ultrastructure; D018345:Mice, Knockout; D016601:RNA-Binding Proteins / Q000502:physiology*
chemical_list: C486565:Caprin1 protein, mouse; D018797:Cell Cycle Proteins; D016601:RNA-Binding Proteins; C542012:caprin2 protein, mouse
keywords: RNA granule component; gene expression; iSyTE; lens nucleus compaction; lenti-corneal stalk; mouse development