TY  - JOUR
TI  - Wnt signaling in hydroid development: ectopic heads and giant buds induced by GSK-3beta inhibitors 
AU  - Muller, Werner
AU  - Frank, Uri
AU  - Teo, Regina
AU  - Mokady, Ofer
AU  - Guette, Christina
AU  - Plickert, Gunter
T2  - The International Journal of Developmental Biology
AB  - In Hydractinia, a colonial marine hydroid representing the basal phylum Cnidaria, Wnt signaling plays a major role in the specification of the primary body axis in embryogenesis and in the establishment of the oral pole during metamorphosis. Here we report supplementing investigations on head regeneration and bud formation in post-metamorphic development. Head and bud formation were accompanied by the expression of Wnt, frizzled and Tcf. Activation of Wnt signaling by blocking GSK-3beta affected regeneration, the patterning of growing polyps and the asexual formation of new polyps in the colony. In the presence of lithium ions or paullones, gastric segments excised from adult polyps showed reversal of tissue polarity as they frequently regenerated heads at both ends. Phorbol myristate acetate, a known activator of protein kinase C increased this effect. Global activation of the Wnt pathway caused growing polyps to form ectopic tentacles and additional heads along their body column. Repeated treatment of colonies evoked the emergence of many and dramatically oversized bud fields along the circumference of the colony. These giant fields fell apart into smaller sub-fields, which gave rise to arrays of multi-headed polyps. We interpret the morphogenetic effects of blocking GSK-3beta as reflecting increase in positional value in terms of positional information and activation of Wnt target genes in molecular terms.
PY  - 2007
DO  - 10.1387/ijdb.062247wm
VL  - 51
IS  - 3
SP  - 211
EP  - 220
J2  - Int. J. Dev. Biol.
LA  - en
SN  - 0214-6282
SN  - 1696-3547
UR  - https://ijdb.ehu.eus/article/062247wm
Y2  - 2024/11/05/13:18:10
ER  -