Baltimore classification

Baltimore classification‏‎ is a system used to categorize viruses based on their manner of mRNA synthesis. The system was developed by Nobel Prize-winning biologist David Baltimore in the early 1970s.

Overview

The Baltimore classification‏‎ system is a key tool in virology, the study of viruses and their functions. It categorizes viruses into seven groups, designated by Roman numerals I through VII. These groups are based on the virus's manner of mRNA synthesis, which is a critical aspect of the virus's lifecycle and replication process.

Classification Groups

The seven groups in the Baltimore classification‏‎ system are:

1. Group I: Double-stranded DNA viruses (e.g., Herpesviridae)
2. Group II: Single-stranded DNA viruses (e.g., Parvoviridae)
3. Group III: Double-stranded RNA viruses (e.g., Reoviridae)
4. Group IV: Positive-sense single-stranded RNA viruses (e.g., Picornaviridae)
5. Group V: Negative-sense single-stranded RNA viruses (e.g., Orthomyxoviridae)
6. Group VI: Positive-sense single-stranded RNA viruses that replicate through a DNA intermediate (e.g., Retroviridae)
7. Group VII: Double-stranded DNA viruses that replicate through a single-stranded RNA intermediate (e.g., Hepadnaviridae)

Each group has unique characteristics and includes a variety of virus families.

Importance

The Baltimore classification‏‎ system is important because it provides a framework for understanding the diverse strategies that viruses use to replicate. This knowledge is crucial for the development of antiviral drugs and vaccines.

See Also

• Virus classification
• Viral replication
• Viral evolution

References

• Baltimore, D. (1971). "Expression of animal virus genomes". Bacteriological Reviews, 35(3), 235–241.