title: Mice develop normally without tenascin.
abstract: Tenascin, an extracellular matrix protein, is expressed in an unusually restricted pattern during embryogenesis and has been implicated in a variety of morphogenetic phenomena. To directly assess the function of tenascin in vivo, we generated mutant mice in which the tenascin gene was nully disrupted by replacing it with the lacZ gene. In mutant mice, lacZ was expressed in place of tenascin, and no tenascin product was detected. Homozygous mutant mice were, however, obtained in accordance with Mendelian laws, and both females and males produced offspring normally. No anatomical or histological abnormalities were detected in any tissues, and no major changes were observed in distribution of fibronectin, laminin, collagen, and proteoglycan. The existence of these mutant mice, lacking tenascin yet phenotypically normal, casts doubt on the theory that tenascin plays and essential role in normal development.
authors.affiliation: Laboratory of Cell Biology, Tsukuba Life Science Center, Institute of Physical and Chemical Research (RIKEN), Ibaraki, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Saga
authors.forename: T
authors.initials: T
authors.lastname: Yagi
authors.forename: Y
authors.initials: Y
authors.lastname: Ikawa
authors.forename: T
authors.initials: T
authors.lastname: Sakakura
authors.forename: S
authors.initials: S
authors.lastname: Aizawa
mesh_terms: D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D015816:Cell Adhesion Molecules, Neuronal / Q000235:genetics / Q000502:physiology*; D002478:Cells, Cultured; D002678:Chimera; D005314:Embryonic and Fetal Development / Q000235:genetics / Q000502:physiology*; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000502:physiology*; D005260:Female; D007150:Immunohistochemistry; D007763:Lac Operon; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008817:Mice, Mutant Strains; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009841:Oligonucleotides; D016133:Polymerase Chain Reaction; D019063:Tenascin; D014162:Transfection
chemical_list: D015816:Cell Adhesion Molecules, Neuronal; D016326:Extracellular Matrix Proteins; D009841:Oligonucleotides; D019063:Tenascin