Mice, KnockoutMice, Inbred C57BLMice, TransgenicMice, Mutant StrainsPhenotypeDisease Models, AnimalMutationSignal TransductionBehavior, AnimalGene TargetingCells, CulturedMolecular Sequence DataCell DifferentiationMaze LearningGene Expression Regulation, DevelopmentalCrosses, GeneticMice, 129 StrainMotor ActivityHomozygoteGene Expression RegulationNerve Tissue ProteinsGene DeletionTranscription FactorsBase SequenceNeuronsRNA, MessengerMice, Inbred StrainsAmino Acid SequenceDNA-Binding ProteinsBrainMesocestoidesReverse Transcriptase Polymerase Chain ReactionGene Knock-In TechniquesGene ExpressionCell ProliferationAgingTime FactorsBlotting, WesternIn Situ HybridizationMembrane ProteinsHeterozygoteImmunohistochemistryExploratory BehaviorApoptosisLiverNervous System MalformationsHomeostasisAnimals, NewbornMice, Inbred BALB CDNA PrimersGenotypeCell LineBody WeightAging, PrematureDwarfismEmbryo, MammalianCarrier ProteinsSpleenHippocampusHomeodomain ProteinsMuscle, SkeletalAnalysis of VarianceTrans-ActivatorsInsulinTransgenesMice, Neurologic MutantsOrgan SizeOsteopetrosisAllelesSpecies SpecificityNuclear ProteinsProtein BindingDendritic SpinesPalateMusculoskeletal AbnormalitiesModels, BiologicalMicroscopy, Electron, TransmissionIntracellular Signaling Peptides and ProteinsInflammationThymus GlandCell CountB-Lymphocyte SubsetsFearOsteoclastsCell DivisionMice, Inbred C3HCytokinesStem CellsOrgan SpecificityCircadian RhythmPhosphorylationGlucoseT-LymphocytesBone and BonesProteinsSkin AbnormalitiesDown-RegulationPromoter Regions, GeneticGroomingHabituation, Psychophysiologic