Wnt pathway components orient a mitotic spindle in the early Caenorhabditis elegans embryo without requiring gene transcription in the responding cell.
In a four-cell-stage Caenorhabditis elegans embryo, Wnt signaling polarizes an endoderm precursor called EMS. The polarization of this cell orients its mitotic spindle in addition to inducing endodermal fate in one daughter cell. Reducing the function of Wnt pathway genes, including a newly identified GSK-3beta homolog called gsk-3, disrupts endoderm induction, whereas only a subset of these genes is required for proper EMS mitotic spindle orientation. Wnt pathway genes thought to act downstream of gsk-3 appear not to be required for spindle orientation, suggesting that gsk-3 represents a branch point in the control of endoderm induction and spindle orientation. Orientation of the mitotic spindle does not require gene transcription in EMS, suggesting that Wnt signaling may directly target the cytoskeleton in a responding cell.
Schlesinger
A
A
Institute of Molecular Biology, University of Oregon, Eugene, Oregon 97403, USA.
Shelton
C A
CA
Maloof
J N
JN
Meneghini
M
M
Bowerman
B
B
D000595:Amino Acid Sequence; D000818:Animals; D001757:Blastomeres / Q000166:cytology / Q000378:metabolism; D017173:Caenorhabditis elegans / Q000166:cytology / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019070:Cell Lineage; D016764:Cell Polarity; D002478:Cells, Cultured; D003599:Cytoskeleton / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000378:metabolism; D047108:Embryonic Development; D004707:Endoderm / Q000166:cytology; D017238:Genes, Helminth / Q000235:genetics / Q000502:physiology; D038362:Glycogen Synthase Kinase 3; D015801:Helminth Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000502:physiology*; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D008941:Spindle Apparatus / Q000378:metabolism*; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics*; D051153:Wnt Proteins; D029961:Zebrafish Proteins
D015801:Helminth Proteins; D011518:Proto-Oncogene Proteins; D051153:Wnt Proteins; D029961:Zebrafish Proteins; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D038362:Glycogen Synthase Kinase 3