title: Development, composition, and structural arrangements of the ciliary zonule of the mouse.
abstract: OBJECTIVE
  Here, we examined the development, composition, and structural organization of the ciliary zonule of the mouse. Fibrillin 1, a large glycoprotein enriched in force-bearing tissues, is a prominent constituent of the mouse zonule. In humans, mutations in the gene for fibrillin 1 (FBN1) underlie Marfan syndrome (MS), a disorder characterized by lens dislocation and other ocular symptoms.
  
  
  METHODS
  Fibrillin expression was analyzed by in situ hybridization. The organization of the zonule was visualized using antibodies to Fbn1, Fbn2, and microfibril-associated glycoprotein-1 (Magp1) in conjunction with 5-ethynyl-2'-deoxyuridine (EdU), an S-phase marker.
  
  
  RESULTS
  Microfibrils, enriched in Fbn2 and Magp1, were prominent components of the temporary vascular tunic of the embryonic lens. Fbn2 expression by nonpigmented ciliary epithelial cells diminished postnatally and there was a concomitant increase in Fbn1 expression, especially in cells located in valleys between the ciliary folds. Zonular fibers projected from the posterior pars plicata to the lens in anterior, equatorial, and posterior groupings. The attachment point of the posterior zonular fibers consisted of a dense meshwork of radially oriented microfibrils that we termed the fibrillar girdle. The fibrillar girdle was located directly above the transition zone, a region of the lens epithelium in which cells commit to terminal differentiation.
  
  
  CONCLUSIONS
  The development and arrangement of the murine ciliary zonule are similar to those of humans, and consequently the mouse eye may be a useful model in which to study ocular complications of MS.
authors.affiliation: Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
authors.forename: Yanrong
authors.initials: Y
authors.lastname: Shi
authors.forename: Yidong
authors.initials: Y
authors.lastname: Tu
authors.forename: Alicia
authors.initials: A
authors.lastname: De Maria
authors.forename: Robert P
authors.initials: RP
authors.lastname: Mecham
authors.forename: Steven
authors.initials: S
authors.lastname: Bassnett
mesh_terms: D000818:Animals; D002924:Ciliary Body / Q000196:embryology* / Q000378:metabolism; D003285:Contractile Proteins / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D000071838:Fibrillin-1; D000071840:Fibrillin-2; D000071837:Fibrillins; D019084:Fluorescent Antibody Technique, Indirect; D017403:In Situ Hybridization; D007908:Lens, Crystalline / Q000196:embryology*; D008022:Ligaments / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D020894:Microfibrils / Q000378:metabolism*; D008840:Microfilament Proteins / Q000378:metabolism*; D018613:Microscopy, Confocal; D020033:Protein Isoforms / Q000378:metabolism; D000072260:RNA Splicing Factors; D016196:S Phase / Q000502:physiology; D054392:Adipokines
chemical_list: D003285:Contractile Proteins; D016326:Extracellular Matrix Proteins; D000071838:Fibrillin-1; D000071840:Fibrillin-2; D000071837:Fibrillins; D008840:Microfilament Proteins; D020033:Protein Isoforms; D000072260:RNA Splicing Factors; C000605722:FBN1 protein, human; D054392:Adipokines; C000605723:FBN2 protein, human; C000605724:Fbn1 protein, mouse; C000605728:Fbn2 protein, mouse; C016598:microfibrillar protein