Mice, KnockoutPhenotypeGene Knockout TechniquesGenomic InstabilityMolecular Sequence DataBase SequenceGenomicsComparative Genomic HybridizationGenomic LibraryMice, Inbred C57BLSequence Analysis, DNAGenomic IslandsGenomePhylogenyAmino Acid SequenceChromosome MappingGenomic ImprintingCloning, MolecularGenome, HumanGenome, BacterialMutationGene DeletionPolymerase Chain ReactionNucleic Acid HybridizationDNAOligonucleotide Array Sequence AnalysisGene Expression ProfilingRNA, MessengerEvolution, MolecularExons