Endogenous RetrovirusesTerminal Repeat SequencesRetroviridae InfectionsRetroviridaeGenes, polProvirusesGenes, envGene Products, envGenome, HumanBetaretrovirusMolecular Sequence DataEvolution, MolecularPhylogenyBase SequenceGenes, Intracisternal A-ParticleGammaretrovirusTranscription, GeneticVirus IntegrationJaagsiekte sheep retrovirusSwine, MiniatureGenes, gagRetroelementsLeukemia Virus, MurineCebidaeGene Products, polSwineGenomeCercopithecidaeGenome, ViralGene Products, gagDNA, ViralSequence Analysis, DNACell Line