title: Winged-helix, Hedgehog and Bmp genes are differentially expressed in distinct cell layers of the murine yolk sac.
abstract: The visceral yolk sac plays a critical role in normal embryogenesis, yet little is known about the specific molecules that regulate its development. We show here that four winged-helix genes (HNF-3alpha, HNF-3beta, HNF-3gamma and HFH-4) are restricted to visceral endoderm. In the absence of HNF-3beta, visceral endoderm forms but the morphogenetic movements by which the embryo becomes enclosed within its yolk sac are disrupted and serum protein gene transcription is greatly reduced. Hedgehog and Bmp genes, which encode signaling molecules known to play multiple roles in embryonic development, are also differentially expressed in the closely apposed yolk sac mesoderm and endoderm layers. Our results suggest that similar mechanisms may be utilized to mediate inductive interactions in both extraembryonic and embryonic tissues.
authors.affiliation: Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
authors.forename: S M
authors.initials: SM
authors.lastname: Farrington
authors.forename: M
authors.initials: M
authors.lastname: Belaoussoff
authors.forename: M H
authors.initials: MH
authors.lastname: Baron
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019485:Bone Morphogenetic Proteins / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism / Q000502:physiology; D029721:Drosophila Proteins; D053823:Hedgehog Proteins; D051541:Hepatocyte Nuclear Factor 3-alpha; D051542:Hepatocyte Nuclear Factor 3-beta; D051543:Hepatocyte Nuclear Factor 3-gamma; D019476:Insect Proteins / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism / Q000502:physiology; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism*; D015017:Yolk Sac / Q000378:metabolism*
chemical_list: D019485:Bone Morphogenetic Proteins; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; C496500:Foxa1 protein, mouse; C496503:Foxa2 protein, mouse; C496506:Foxa3 protein, mouse; D053823:Hedgehog Proteins; D051541:Hepatocyte Nuclear Factor 3-alpha; D019476:Insect Proteins; D009687:Nuclear Proteins; D014157:Transcription Factors; D051543:Hepatocyte Nuclear Factor 3-gamma; D051542:Hepatocyte Nuclear Factor 3-beta; C077245:hh protein, Drosophila