List of Figures. List of Tables. List of Contributors. Preface. Acknowledgements. 1. Genome of RNA Viruses; F. H?ricourt, et al. 2. Genome of DNA Viruses; T. Frischmuth. 3. Genome Organization in RNA Viruses; S. Morozov, A. Solovyev. 4. Gene Expression in Positive Strand RNA Viruses: Conventional and Aberrant Strategies; A. Agranovsky, S. Morozov. 5. Molecular Basis of Genetic Variability in RNA Viruses; J.J. Bujarski. 6. Genetic Variability and Evolution; F. Garcia-Arenal, et al. 7. Molecular Basis of Virus Transport in Plants; S.M. Leisner. 8. Molecular Basis of Virus Transmission; J.F.J.M. van den Heuvel, et al. 9. Molecular Basis of Symptomatology; A.L.N. Rao. 10. Gene-for-Gene Interactions; C.D. Dardick, J.N. Culver. 11. Molecular Biology of Viroids; R. Flores, et al. 12. Molecular Biology of Transgenic Plants; C.L. Mandahar. 13. Gene Silencing; C.L. Mandahar. Subject Index.