title: Expression and function of mouse Sox17 gene in the specification of gallbladder/bile-duct progenitors during early foregut morphogenesis.
abstract: In early-organogenesis-stage mouse embryos, the posteroventral foregut endoderm adjacent to the heart tube gives rise to liver, ventral pancreas and gallbladder. Hepatic and pancreatic primordia become specified in the posterior segment of the ventral foregut endoderm at early somite stages. The mechanisms for demarcating gallbladder and bile duct primordium, however, are poorly understood. Here, we demonstrate that the gallbladder and bile duct progenitors are specified in the paired lateral endoderm domains outside the heart field at almost the same timing as hepatic and pancreatic induction. In the anterior definitive endoderm, Sox17 reactivation occurs in a certain population within the most lateral domains posterolateral to the anterior intestinal portal (AIP) lip on both the left and right sides. During foregut formation, the paired Sox17-positive domains expand ventromedially to merge in the midline of the AIP lip and become localized between the liver and pancreatic primordia. In Sox17-null embryos, these lateral domains are missing, resulting in a complete loss of the gallbladder/bile-duct structure. Chimera analyses revealed that Sox17-null endoderm cells in the posteroventral foregut do not display any gallbladder/bile-duct molecular characters. Our findings show that Sox17 functions cell-autonomously to specify gallbladder/bile-duct in the mouse embryo.
authors.affiliation: Department of Veterinary Anatomy, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Mami
authors.initials: M
authors.lastname: Uemura
authors.forename: Kenshiro
authors.initials: K
authors.lastname: Hara
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Shitara
authors.forename: Rie
authors.initials: R
authors.lastname: Ishii
authors.forename: Naoki
authors.initials: N
authors.lastname: Tsunekawa
authors.forename: Yutaroh
authors.initials: Y
authors.lastname: Miura
authors.forename: Masamichi
authors.initials: M
authors.lastname: Kurohmaru
authors.forename: Choji
authors.initials: C
authors.lastname: Taya
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Yonekawa
authors.forename: Masami
authors.initials: M
authors.lastname: Kanai-Azuma
authors.forename: Yoshiakira
authors.initials: Y
authors.lastname: Kanai
mesh_terms: D000818:Animals; D001652:Bile Ducts / Q000002:abnormalities / Q000196:embryology* / Q000378:metabolism; D019521:Body Patterning; D004622:Embryo, Mammalian / Q000378:metabolism; D004707:Endoderm / Q000378:metabolism; D005260:Female; D005704:Gallbladder / Q000002:abnormalities / Q000196:embryology* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D024002:HMGB Proteins / Q000235:genetics / Q000502:physiology*; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000196:embryology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009024:Morphogenesis; D055760:SOXF Transcription Factors / Q000235:genetics / Q000502:physiology*
chemical_list: D024002:HMGB Proteins; D055760:SOXF Transcription Factors; C511606:Sox17 protein, mouse