title: Transdifferentiation of mouse visceral yolk sac cells into parietal yolk sac cells in vitro.
abstract: The mouse embryonic yolk sac is an extraembryonic membrane that consists of a visceral yolk sac (VYS) and parietal yolk sac (PYS), and functions in hematopoietic-circulation in the fetal stage. The present study was undertaken to examine the normal development of both murine VYS and PYS tissues using various molecular markers, and to establish a novel VYS cell culture system in vitro for analyzing differentiation potentials of VYS cells. RT-PCR and immunohistochemical analyses of gene expression in VYS and PYS tissues during development revealed several useful markers for their identification: HNF1β, HNF4α, Cdh1 (E-cadherin), Krt8 and Krt18 for VYS epithelial cells, and Stra6, Snail1, Thbd and vimentin for PYS cells. PYS cells exhibited mesenchymal characteristics in gene expression and morphology. When VYS cells at 11.5 days of gestation were cultured in vitro for 7 days, the number of HNF1β-, HNF4α-, E-cadherin- and cytokeratin-positive VYS epithelial cells was significantly reduced and, instead, Stra6-and vimentin-positive PYS-like cells increased with culture. RT-PCR analyses also demonstrated that gene expression of VYS markers decreased, whereas that of PYS markers increased in the primary culture of VYS cells. These data indicate that VYS epithelial cells rapidly transdifferentiate into PYS cells having mesenchymal characteristics in vitro, which may provide a culture system suitable for studying molecular mechanisms of VYS transdifferentiation into PYS cells and also epithelial-mesenchymal transition.
authors.affiliation: Graduate School of Science and Technology, Shizuoka University, Oya 836, Suruga-ku, Shizuoka City, Shizuoka 422-8529, Japan.
authors.forename: Shinomi
authors.initials: S
authors.lastname: Yagi
authors.affiliation: Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 B51, Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8501, Japan.
authors.forename: Yoh-ichi
authors.initials: Y
authors.lastname: Tagawa
authors.affiliation: Graduate School of Science and Technology, Shizuoka University, Oya 836, Suruga-ku, Shizuoka City, Shizuoka 422-8529, Japan. Electronic address: shiojiri.nobuyoshi@shizuoka.ac.jp.
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Shiojiri
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000502:physiology*; D002478:Cells, Cultured; D047108:Embryonic Development / Q000502:physiology*; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000502:physiology; D051379:Mice; D008809:Mice, Inbred C3H; D014781:Viscera / Q000166:cytology* / Q000502:physiology; D015017:Yolk Sac / Q000166:cytology* / Q000502:physiology
keywords: EMT; Parietal yolk sac; Transdifferentiation; Visceral yolk sac