Selection, GeneticClonal EvolutionClone CellsClonal Selection, Antigen-MediatedClonal DeletionImmunoglobulin Variable RegionImmunoglobulin Heavy ChainsMutationGenes, ImmunoglobulinB-LymphocytesReceptors, Antigen, B-CellCell Transformation, NeoplasticMolecular Sequence DataKaryotypingBase SequenceReceptors, Antigen, T-CellPhenotypeMice, Inbred C57BLT-LymphocytesCells, CulturedCell DifferentiationPolymerase Chain ReactionCell LineModels, GeneticEvolution, MolecularBiological EvolutionGenetic Variation