title: Restriction of mesendoderm to a single blastomere by the combined action of SKN-1 and a GSK-3beta homolog is mediated by MED-1 and -2 in C. elegans.
abstract: The endoderm and much of the mesoderm arise from the EMS cell in the four-cell C. elegans embryo. We report that the MED-1 and -2 GATA factors specify the entire fate of EMS, which otherwise produces two C-like mesectodermal progenitors. The meds are direct targets of the maternal SKN-1 transcription factor; however, their forced expression can direct SKN-1-independent reprogramming of non-EMS cells into mesendodermal progenitors. We find that SGG-1/GSK-3beta kinase acts both as a Wnt-dependent activator of endoderm in EMS and an apparently Wnt-independent repressor of the meds in the C lineage, indicating a dual role for this kinase in mesendoderm development. Our results suggest that a broad tissue territory, mesendoderm, in vertebrates has been confined to a single cell in nematodes through a common gene regulatory network.
authors.affiliation: Department of Molecular, Cellular, and Developmental Biology and Neuroscience Research Institute, University of California, Santa Barbara 93106, USA.
authors.forename: M F
authors.initials: MF
authors.lastname: Maduro
authors.forename: M D
authors.initials: MD
authors.lastname: Meneghini
authors.forename: B
authors.initials: B
authors.lastname: Bowerman
authors.forename: G
authors.initials: G
authors.lastname: Broitman-Maduro
authors.forename: J H
authors.initials: JH
authors.lastname: Rothman
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001757:Blastomeres / Q000166:cytology / Q000378:metabolism*; D017173:Caenorhabditis elegans / Q000166:cytology / Q000196:embryology / Q000235:genetics / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism; D002454:Cell Differentiation; D019070:Cell Lineage; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004707:Endoderm / Q000166:cytology / Q000378:metabolism*; D050981:Erythroid-Specific DNA-Binding Factors; D050980:GATA Transcription Factors; D038362:Glycogen Synthase Kinase 3; D015801:Helminth Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008648:Mesoderm / Q000166:cytology / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000502:physiology; D016601:RNA-Binding Proteins; D015398:Signal Transduction; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051153:Wnt Proteins; D029961:Zebrafish Proteins
chemical_list: D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D050980:GATA Transcription Factors; D015801:Helminth Proteins; C433251:MED-1 protein, C elegans; C433252:MED-2 protein, C elegans; C117258:POS-1 protein, C elegans; D011518:Proto-Oncogene Proteins; D016601:RNA-Binding Proteins; D014157:Transcription Factors; D051153:Wnt Proteins; D029961:Zebrafish Proteins; C073702:skn-1 protein, C elegans; D004247:DNA; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D038362:Glycogen Synthase Kinase 3