Abstract
AbstractIn vertebrate embryos, the canonical Wnt ligand primes the formation of dorsal organizers that govern dorsal-ventral patterns by secreting BMP antagonists. In contrast, in Drosophila embryos, Toll-like receptor (Tlr)-mediated NFκB activation initiates dorsal-ventral patterning, wherein Wnt-mediated negative feedback regulation of Tlr/NFκB generates a BMP antagonist-secreting signalling centre to control the dorsal-ventral pattern. Although both Wnt and BMP antagonist are conserved among species, the involvement of Tlr/NFκB and feedback regulation in vertebrate organizer formation remains unclear. By imaging and genetic modification, we reveal that a negative feedback loop between canonical and non-canonical Wnts and Tlr4/NFκB determines the size of zebrafish organizer, and that Tlr/NFκB and Wnts switch initial cue and feedback mediator roles between Drosophila and zebrafish. Here, we show that canonical Wnt signalling stimulates the expression of the non-canonical Wnt5b ligand, activating the Tlr4 receptor to stimulate NFκB-mediated transcription of the Wnt antagonist frzb, restricting Wnt-dependent dorsal organizer formation.
Funder
MEXT | Japan Society for the Promotion of Science
MEXT | Japan Science and Technology Agency
Takeda Science Foundation
Mitsubishi Foundation
Daiichi Sankyo Foundation of Life Science
Uehara Memorial Foundation
Mochida Memorial Foundation for Medical and Pharmaceutical Research
Ono Medical Research Foundation
Secom Science and Technology Foundation
Naito Foundation
Publisher
Springer Science and Business Media LLC
Subject
General Physics and Astronomy,General Biochemistry, Genetics and Molecular Biology,General Chemistry,Multidisciplinary
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