Twinning, MonozygoticGenetic DeterminismCloning, OrganismCloning, MolecularMammalsClone CellsMolecular Sequence DataBase SequenceAmino Acid SequenceDNA, ComplementarySequence Homology, Amino AcidSequence AlignmentSequence Analysis, DNAEscherichia coliSequence Homology, Nucleic AcidGenes, BacterialDNARNA, MessengerPhylogenyPlasmidsPolymerase Chain ReactionRestriction MappingRecombinant ProteinsChromosome MappingGenesNucleic Acid HybridizationGene ExpressionBlotting, SouthernDNA, BacterialCell LineBlotting, NorthernDNA Restriction EnzymesDNA PrimersMutationSpecies SpecificityTranscription, GeneticGene LibraryDNA, RecombinantOpen Reading FramesMultigene FamilyBacterial ProteinsGenomic LibraryGenetic Complementation TestGene Expression RegulationGenetic VectorsBiological EvolutionPhenotypeTissue DistributionEvolution, MolecularCosmids