Wnt signaling in hydroid development: formation of the primary body axis in embryogenesis and its subsequent patterning.
We have studied the role the canonical Wnt pathway plays in hydroid pattern formation during embryonic development and metamorphosis. Transcripts of Wnt and Tcf were asymmetrically deposited in the oocyte and subsequent developmental stages, marking the sites of first cleavage, posterior larval pole and the upcoming head of the metamorphosed polyp. To address the function of these genes, we activated downstream events of the Wnt pathway by pharmacologically blocking GSK-3beta. These treatments rendered the polar expression of Tcf ubiquitous and induced development of ectopic axes that contained head structures. These results allow concluding that Wnt signaling controls axis formation and regional tissue fates along it, determining one single axis terminus from which later the mouth and hypostome develop. Our data also indicate Wnt functions in axis formation and axial patterning as in higher metazoans, and thus point to an ancestral role of Wnt signaling in these processes in animal evolution.
Plickert
Günter
G
Institute of Zoology, University of Cologne, Germany. g.plickert@uni-koeln.de
Jacoby
Vered
V
Frank
Uri
U
Müller
Werner A
WA
Mokady
Ofer
O
D000595:Amino Acid Sequence; D000818:Animals; D001499:Bayes Theorem; D001552:Benzazepines / Q000494:pharmacology; D019521:Body Patterning; D002678:Chimera / Q000196:embryology / Q000235:genetics / Q000378:metabolism; D004625:Embryo, Nonmammalian; D047108:Embryonic Development; D005775:Gastrula / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors; D000071679:Glycogen Synthase Kinase 3 beta; D006829:Hydra / Q000196:embryology*; D007211:Indoles / Q000494:pharmacology; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D051820:TCF Transcription Factors / Q000235:genetics; D051153:Wnt Proteins / Q000235:genetics / Q000378:metabolism*
D001552:Benzazepines; D007211:Indoles; D051820:TCF Transcription Factors; D051153:Wnt Proteins; C120793:alsterpaullone; D000071679:Glycogen Synthase Kinase 3 beta; D038362:Glycogen Synthase Kinase 3