Inhibitory interactions controlling organizer activity in fish.
An experimental system allowing the observation of 2 active organizing centers during zebrafish development is described. It was achieved by injection into a single marginal cell at the 16-cell stage of TARAM-A-D mRNA. TARAM-A-D was previously described as the mutated constitutive form of a type I receptor for transforming growth factor beta. In 80% of the injected embryos, 2 distinct organizers were observed at the onset of gastrulation. At the end of gastrulation, these embryos showed duplicated axial structures. Nevertheless, only 25% of the injected embryos displayed a recognizable axis duplication after 1 day of development. This paradox is taken as an evidence for suppressive effects exerted in a reciprocal manner when more than 1 organizing center is present.
Peyriéras
N
N
INSERM U. 368 Ecole normale supérieure, Paris, France.
Lu
Y
Y
Renucci
A
A
Lemarchandel
V
V
Rosa
F
F
D000818:Animals; D008648:Mesoderm / Q000166:cytology / Q000187:drug effects; D009154:Mutation; D009697:Nucleolus Organizer Region; D012333:RNA, Messenger / Q000235:genetics / Q000494:pharmacology; D016212:Transforming Growth Factor beta / Q000235:genetics; D015027:Zebrafish / Q000196:embryology*
D012333:RNA, Messenger; D016212:Transforming Growth Factor beta