IntronsRNA SplicingMolecular Sequence DataBase SequenceExonsMammalsAmino Acid SequenceSpliceosomesCloning, MolecularEvolution, MolecularRNA PrecursorsPhylogenyRNA Splice SitesSequence AlignmentSequence Homology, Amino AcidSequence Homology, Nucleic AcidRNA, MessengerAlternative SplicingNucleic Acid ConformationGenesConserved SequenceDNADNA, ComplementaryTranscription, GeneticCell LineSpecies SpecificitySequence Analysis, DNAMutationBiological EvolutionRNA, Small NuclearModels, GeneticRestriction MappingHeLa CellsGenomeOpen Reading FramesRNA, CatalyticEmbryo, MammalianChromosome MappingPolymerase Chain ReactionSaccharomyces cerevisiaeRNARNA, FungalDNA PrimersGenes, FungalGene Expression RegulationPromoter Regions, GeneticEuglena gracilis