HomozygoteMice, Mutant StrainsGene TargetingMice, KnockoutMutationHeterozygotePhenotypeMice, Inbred C57BLMice, TransgenicGene Expression Regulation, DevelopmentalMolecular Sequence DataEmbryo, MammalianBase SequenceHomeodomain ProteinsDNA-Binding ProteinsTranscription FactorsGenotypeDisease Models, AnimalSequence DeletionMice, Neurologic MutantsRNA, MessengerGenes, LethalEmbryonic and Fetal DevelopmentMutagenesis, InsertionalCrosses, GeneticMutant ProteinsGene DeletionAllelesIn Situ HybridizationChimeraGenetic Complementation TestEthylnitrosoureaAmino Acid SequenceDNA PrimersMorphogenesisMutagenesis, Site-DirectedEmbryo LossSignal TransductionSkeletonPoint MutationCell LineFetal DeathMembrane ProteinsNerve Tissue ProteinsCloning, MolecularChromosome MappingEscherichia coliCell DifferentiationDrosophila ProteinsArabidopsisGastrulaGene ExpressionSequence Homology, Amino AcidZebrafishRepressor ProteinsPolymerase Chain ReactionBacterial ProteinsNuclear ProteinsFertilityStem CellsEmbryonic DevelopmentMutagenesisCells, CulturedBody PatterningGenes, RecessiveCraniofacial AbnormalitiesTrans-ActivatorsFoot BonesCarrier ProteinsGenes, HomeoboxMesodermAnimals, NewbornProtein Structure, TertiaryRestriction MappingRecombination, GeneticLac OperonPaired Box Transcription FactorsArabidopsis ProteinsTranscription, GeneticDrosophila melanogasterImmunohistochemistryCell DivisionAmino Acid SubstitutionRecombinant Fusion ProteinsDrosophilaTransfectionBrainExonsReverse Transcriptase Polymerase Chain ReactionProteinsNeuronsMice, Inbred StrainsAnimals, Genetically ModifiedMice, Inbred C3HPregnancyBlotting, WesternBlotting, SouthernZebrafish ProteinsProtein BindingSpermatogenesis