title: Defective development of the gall bladder and cystic duct in Lgr4- hypomorphic mice.
abstract: Leucine-rich repeat (LRR) -containing G protein coupled receptor (LGR) family members are characterized by the presence of a seven-transmembrane domain and LRR motifs. We describe a new function for Lgr4 in the development of the gall bladder and cystic duct and in the epithelium-mesenchyme interaction. Lgr4 expression was observed in the gall bladder epithelium when the gall bladder primordium elongated ventrally. Although Lgr4 hypomorphic mutant (Lgr4(Gt/Gt)) embryos developed a normal gall bladder bud at embryonic day (E) 10.25, no further elongation was observed at later stages. At E12.5, the mesenchyme surrounding the gall bladder had completely disappeared in Lgr4(Gt/Gt) embryos, while the gall bladder remained unelongated. Neighboring tissues such as liver and pancreas were unaffected, as revealed by expression of marker genes. This is the first report of a mutant mouse that lacks a gall bladder and cystic duct without affecting the other tissues that derive from the same hepatic diverticulum.
authors.affiliation: Division of Developmental Genetics, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Yamashita
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Takegawa
authors.forename: Machiko
authors.initials: M
authors.lastname: Sakumoto
authors.forename: Mai
authors.initials: M
authors.lastname: Nakahara
authors.forename: Haruna
authors.initials: H
authors.lastname: Kawazu
authors.forename: Takayuki
authors.initials: T
authors.lastname: Hoshii
authors.forename: Kimi
authors.initials: K
authors.lastname: Araki
authors.forename: Yuji
authors.initials: Y
authors.lastname: Yokouchi
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Yamamura
mesh_terms: D000818:Animals; D003549:Cystic Duct / Q000002:abnormalities* / Q000196:embryology / Q000378:metabolism*; D004622:Embryo, Mammalian / Q000196:embryology / Q000378:metabolism; D004848:Epithelium / Q000196:embryology / Q000378:metabolism; D005704:Gallbladder / Q000002:abnormalities* / Q000196:embryology / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D008648:Mesoderm / Q000196:embryology / Q000378:metabolism; D051379:Mice; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism*
chemical_list: C496200:LGR4 protein, mouse; D043562:Receptors, G-Protein-Coupled