title: Roles of cell-adhesion molecules nectin 1 and nectin 3 in ciliary body development.
abstract: Nectins are Ca2+-independent immunoglobulin-like cell-cell-adhesion molecules consisting of four members. Nectins homophilically and heterophilically trans-interact to form a variety of cell-cell junctions, including cadherin-based adherens junctions in epithelial cells and fibroblasts in culture, synaptic junctions in neurons, and Sertoli cell-spermatid junctions in the testis, in cooperation with, or independently of, cadherins. To further explore the function of nectins, we generated nectin 1-/- and nectin 3-/-)mice. Both nectin 1-/- and nectin 3-/- mice showed a virtually identical ocular phenotype, microphthalmia, accompanied by a separation of the apex-apex contact between the pigment and non-pigment cell layers of the ciliary epithelia. Immunofluorescence and immunoelectron microscopy revealed that nectin 1 and nectin 3, but not nectin 2, localized at the apex-apex junctions between the pigment and non-pigment cell layers of the ciliary epithelia. However, nectin 1-/- and nectin 3-/- mice showed no impairment of the apicolateral junctions between the pigment epithelia where nectin 1, nectin 2 and nectin 3 localized, or of the apicolateral junctions between the non-pigment epithelia where nectin 2 and nectin 3, but not nectin 1, localized. These results indicate that the heterophilic trans-interaction between nectin 1 and nectin 3 plays a sentinel role in establishing the apex-apex adhesion between the pigment and non-pigment cell layers of the ciliary epithelia that is essential for the morphogenesis of the ciliary body.
authors.affiliation: Department of Molecular Biology and Biochemistry, Osaka University Graduate School of Medicine/Faculty of Medicine, Suita 565-0871, Japan.
authors.forename: Maiko
authors.initials: M
authors.lastname: Inagaki
authors.forename: Kenji
authors.initials: K
authors.lastname: Irie
authors.forename: Hiroyoshi
authors.initials: H
authors.lastname: Ishizaki
authors.forename: Miki
authors.initials: M
authors.lastname: Tanaka-Okamoto
authors.forename: Koji
authors.initials: K
authors.lastname: Morimoto
authors.forename: Eiji
authors.initials: E
authors.lastname: Inoue
authors.forename: Toshihisa
authors.initials: T
authors.lastname: Ohtsuka
authors.forename: Jun
authors.initials: J
authors.lastname: Miyoshi
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Takai
mesh_terms: D000818:Animals; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000502:physiology*; D002924:Ciliary Body / Q000196:embryology* / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008850:Microphthalmos / Q000235:genetics / Q000473:pathology; D000075983:Nectins; D012333:RNA, Messenger / Q000502:physiology
chemical_list: D015815:Cell Adhesion Molecules; C000619015:Nectin1 protein, mouse; C000619017:Nectin3 protein, mouse; D000075983:Nectins; D012333:RNA, Messenger