This document provides an introduction to virology, discussing the nature of viruses and their genomes. It explains that viruses need living cells to survive and have either DNA or RNA genomes that are single or double stranded. It describes why viruses are studied, noting they can infect all life and led to discoveries in molecular biology. Some major milestones are discussed, like contributions of bacteriophages to molecular biology and understanding cancer from tumor viruses. Viruses can also be engineered as vector viruses to insert genes into hosts for therapeutic purposes. Common detection techniques like plaque forming and hemagglutination assays are also mentioned.

1. Introduction to Virology

2. Nature of Viruses
Viral genome is packaged in protein coat

3. Virus Genomes

4. Nature of Viruses
• Viruses need a living cell to survive
• Viral genome is released inside the
cytoplasm of the host cell
• Virus genomes are made of DNA or RNA
– Not both
– Single stranded (ss) OR double stranded (ds)

5. Why Study Viruses

7. Why Study Viruses
• Viruses are capable of infecting all forms of life
– Vertebrates, prokaryotes, fungi, algae
• Most abundant form of life
– Bacteriophages are extremely abundant
– Estimated 1031 tailed bacteriophages
• Excellent molecular biology tools

8. Viruses And Molecular Biology
• Study of viruses small DNA viruses led to discovery of
promoters for eukaryotic RNA polymerases
• Study of cancer producing viruses led to discovery of
many cellular oncogenes
• RNA splicing in eukaryotic cells was discovered by
studying mRNA from DNA viruses
• Understanding of cellular DNA replication was facilitated
by studying phages and DNA viral replication

10. Major Virology Milestones

11. Major Virology Milestones
• “Phage” group made significant discoveries/contributions
to the field of molecular biology
• Bacteriophages hold promise as antibiotics
• Particularly in antibiotic resistant bacteria
• Immune reaction to phages remains a serious
obstacle
• Study of tumor viruses let to a clearer understanding of
cancer

12. Viruses As Vectors
• Viruses can be engineered to carry exogenous genes
• The exogenous genes can be inserted in the host’s genome
•When utilizing a virus to insert genes into a host, we refer to
that virus as a Vector Virus
•Vector virus hold promise as therapeutic agents
•Immune response remains an issue

13. Detection And Measurement of Viruses
•Plaque Forming Assay
•Initially done with bacteriophages and bacteria

15. Detection And Measurement of Viruses
•Hemagglutination Assay
•Rapid and convenient

16. Detection And Measurement of Viruses