Organizers, EmbryonicNucleolus Organizer RegionGoosecoid ProteinBody PatterningEmbryonic InductionGastrulaXenopus ProteinsSilver StainingEmbryologyGene Expression Regulation, DevelopmentalOtx Transcription FactorsEmbryo, NonmammalianZebrafish ProteinsHomeodomain ProteinsXenopusMesodermFibroblast Growth Factor 8Nodal ProteinRhombencephalonNotochordHydraMesencephalonAxisNodal Signaling LigandsZebrafishIntercellular Signaling Peptides and ProteinsWnt ProteinsHeadIn Situ HybridizationEctodermXenopus laevisBone Morphogenetic ProteinsTissue TransplantationNervous SystemLIM-Homeodomain ProteinsMorphogenesisSilverCell NucleolusGenes, HomeoboxWnt1 ProteinActivinsLeft-Right Determination FactorsTranscription FactorsEndodermSignal TransductionMetencephalonBlastulaFetal ProteinsT-Box Domain Proteins