Epithelial CellsEpitheliumCadherinsEpithelial-Mesenchymal TransitionMesodermCell ShapeVimentinCell DifferentiationKeratinsCell AdhesionMicroscopy, ElectronCell LineKaryotypingCells, CulturedCell DivisionPhenotypeTumor Cells, CulturedCell MovementImmunohistochemistryReverse Transcriptase Polymerase Chain ReactionTranscription FactorsRNA, MessengerMicroscopy, Electron, ScanningMicroscopy, Electron, TransmissionFossilsDendritesCell SizeMutationSkullPhylogenyBiological EvolutionMolecular Sequence DataTime FactorsMorphogenesisMicroscopy, ConfocalDendritic SpinesSpermatozoaSpecies SpecificityNeuronsMicroscopy, Phase-ContrastActinsMicroscopy, FluorescenceCytoskeletonImaging, Three-DimensionalSperm MotilityCulture MediaAnatomy, ComparativeStaining and LabelingModels, BiologicalOrganelle ShapeCell CountSperm CountImage Processing, Computer-AssistedMandibleMicroscopySurface PropertiesBiomechanical PhenomenaMitochondriaHominidaeGreen Fluorescent ProteinsCephalometryMice, Inbred C57BLFacial BonesApoptosisPaleontologyToothGene Expression Regulation, DevelopmentalCell SurvivalLarvaInfertility, MaleCell Culture TechniquesFibroblastsAmino Acid SequenceHistocytochemistryAxonsOrgan SizeSignal TransductionMicroscopy, Atomic ForceParticle SizeRats, Sprague-DawleyFluorescent Antibody TechniqueMembrane ProteinsBase SequenceCell ProliferationSemen AnalysisPregnancyAnthropology, PhysicalCell NucleusCell MembraneSperm HeadDisease Models, AnimalFlowersMice, KnockoutAnimals, NewbornSemenDinosaursEmbryo, MammalianSequence Analysis, DNAMaxillofacial DevelopmentX-Ray Microtomography