Mice, KnockoutPhenotypeVertebratesGene Knockout TechniquesZebrafishMolecular Sequence DataGene Expression Regulation, DevelopmentalAmino Acid SequenceEvolution, MolecularZebrafish ProteinsChordata, NonvertebrateMice, Inbred C57BLEmbryo, NonmammalianBody PatterningBase SequenceFishesBiological EvolutionLampreysSequence Homology, Amino AcidHagfishesIn Situ HybridizationReptilesInvertebratesSignal TransductionSequence AlignmentHomeodomain ProteinsSpecies SpecificityXenopus ProteinsConserved SequenceTranscription FactorsChickensAnimals, Genetically ModifiedAmphibiansChordataGenomeGene DuplicationCiona intestinalisSharksOryziasMutationTakifuguXenopusPetromyzonCloning, MolecularRNA, MessengerMammalsDrosophila ProteinsChick EmbryoMorphogenesisGenes, HomeoboxXenopus laevis