Distinct WNT pathways regulating AER formation and dorsoventral polarity in the chick limb bud.
The apical ectodermal ridge (AER) is an essential structure for vertebrate limb development. Wnt3a is expressed during the induction of the chick AER, and misexpression of Wnt3a induces ectopic expression of AER-specific genes in the limb ectoderm. The genes beta-catenin and Lef1 can mimic the effect of Wnt3a, and blocking the intrinsic Lef1 activity disrupts AER formation. Hence, Wnt3a functions in AER formation through the beta-catenin/LEF1 pathway. In contrast, neither beta-catenin nor Lef1 affects the Wnt7a-regulated dorsoventral polarity of the limb. Thus, two related Wnt genes elicit distinct responses in the same tissues by using different intracellular pathways.
Kengaku
M
M
Department of Genetics, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA.
Capdevila
J
J
Rodriguez-Esteban
C
C
De La Peña
J
J
Johnson
R L
RL
Izpisúa Belmonte
J C
JC
Tabin
C J
CJ
D000595:Amino Acid Sequence; D000818:Animals; D030161:Avian Proteins; D001483:Base Sequence; D019521:Body Patterning; D002642:Chick Embryo; D003001:Cloning, Molecular; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004475:Ectoderm / Q000378:metabolism*; D051519:Fibroblast Growth Factor 4; D051524:Fibroblast Growth Factor 8; D005346:Fibroblast Growth Factors / Q000096:biosynthesis / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D005964:Glucosyltransferases; D006133:Growth Substances / Q000096:biosynthesis / Q000235:genetics; D018398:Homeodomain Proteins / Q000235:genetics; D036341:Intercellular Signaling Peptides and Proteins; D018878:Limb Buds / Q000196:embryology / Q000378:metabolism*; D051821:Lymphoid Enhancer-Binding Factor 1; D008648:Mesoderm / Q000378:metabolism; D008969:Molecular Sequence Data; D009024:Morphogenesis; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics* / Q000502:physiology; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000502:physiology; D015398:Signal Transduction; D015534:Trans-Activators; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation; D051153:Wnt Proteins; D060508:Wnt3 Protein; D060509:Wnt3A Protein; D051176:beta Catenin
D030161:Avian Proteins; D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins; D051519:Fibroblast Growth Factor 4; D006133:Growth Substances; D018398:Homeodomain Proteins; D036341:Intercellular Signaling Peptides and Proteins; D051821:Lymphoid Enhancer-Binding Factor 1; D011506:Proteins; D011518:Proto-Oncogene Proteins; D015534:Trans-Activators; D014157:Transcription Factors; C555510:WNT3A protein, human; C490509:WNT7A protein, Gallus gallus; D051153:Wnt Proteins; D060508:Wnt3 Protein; D060509:Wnt3A Protein; D051176:beta Catenin; D051524:Fibroblast Growth Factor 8; D005346:Fibroblast Growth Factors; D005964:Glucosyltransferases; C491318:RFNG protein, human