title: Indian hedgehog signaling in extraembryonic endoderm and ectoderm differentiation in ES embryoid bodies.
abstract: We previously demonstrated that a member of the Hedgehog gene family, Indian hedgehog (Ihh), is expressed in the visceral endoderm of EC and ES cell embryoid bodies and mouse embryos. Overexpression studies suggested that Ihh was involved in visceral endoderm differentiation. We now provide evidence for a Hh response in the embryoid body core and in the mesothelial layer of the visceral yolk sac. We also demonstrate that treatment of ES embryoid bodies with the Hh antagonists cAMP and forskolin results in downregulation of the Hh response and altered embryoid body differentiation. The outer endoderm layer undergoes a transition to parietal endoderm while formation of an embryonic ectoderm layer surrounding a cavity is inhibited. These treatments also result in a decrease in the expression of markers for the mesoderm derivatives, blood and endothelial cells. We present a model to explain how Ihh and BMP signaling may regulate extraembryonic endoderm and embryonic ectoderm differentiation.
authors.affiliation: Biology Department, Wesleyan University, Middletown, CT 06459-0170, USA.
authors.forename: P
authors.initials: P
authors.lastname: Maye
authors.forename: S
authors.initials: S
authors.lastname: Becker
authors.forename: E
authors.initials: E
authors.lastname: Kasameyer
authors.forename: N
authors.initials: N
authors.lastname: Byrd
authors.forename: L
authors.initials: L
authors.lastname: Grabel
mesh_terms: D000818:Animals; D015415:Biomarkers; D055396:Bone Morphogenetic Protein 2; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins / Q000235:genetics; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology*; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004475:Ectoderm / Q000166:cytology / Q000502:physiology; D004622:Embryo, Mammalian / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D004627:Embryonic Induction / Q000235:genetics; D004707:Endoderm / Q000166:cytology / Q000502:physiology; D004727:Endothelium / Q000378:metabolism; D005312:Fetal Blood / Q000187:drug effects / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D053823:Hedgehog Proteins; D047908:Intracellular Signaling Peptides and Proteins; D051741:Kruppel-Like Transcription Factors; D008565:Membrane Proteins; D051379:Mice; D009419:Nerve Tissue Proteins; D015513:Oncogene Proteins / Q000235:genetics / Q000378:metabolism; D000072079:Patched Receptors; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D011956:Receptors, Cell Surface; D012097:Repressor Proteins; D015398:Signal Transduction; D015534:Trans-Activators; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D016212:Transforming Growth Factor beta; D029867:Xenopus Proteins; D000071676:Zinc Finger Protein GLI1; D000075746:Zinc Finger Protein Gli2; D000074290:Zinc Finger Protein Gli3
chemical_list: D015415:Biomarkers; C525719:Bmp2 protein, mouse; C525810:Bmp4 protein, mouse; D055396:Bone Morphogenetic Protein 2; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins; D004268:DNA-Binding Proteins; C108003:GLI3 protein, Xenopus; C065683:GLI3 protein, human; C000618551:Gli2 protein, mouse; C465571:Gli3 protein, mouse; D053823:Hedgehog Proteins; D047908:Intracellular Signaling Peptides and Proteins; D051741:Kruppel-Like Transcription Factors; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D015513:Oncogene Proteins; D000072079:Patched Receptors; D011506:Proteins; D011956:Receptors, Cell Surface; D012097:Repressor Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D016212:Transforming Growth Factor beta; D029867:Xenopus Proteins; D000071676:Zinc Finger Protein GLI1; D000075746:Zinc Finger Protein Gli2; D000074290:Zinc Finger Protein Gli3; C525812:bmp4 protein, Xenopus; D005576:Colforsin; D000242:Cyclic AMP