Virology Spring 2023
Chapter 26 Review Guide
General characteristics of Poxviruses
General size, shape, capsid structure/type, genome (number, if applicable, and type)
Size – large
Shape – large ovoid to brick shape structure
Capsid – NO CAPSID
Genome – dsDNA, 150-250 kb
In terms of capsid structure, how are poxviruses different than other animal viruses we covered?
They do not have a capsid
What disease does variola virus cause?
Smallpox, humans only
What disease does vaccina virus cause? Why important in human health history?
Variant of cowpox, most of what we know about poxviruses is from studying vaccina virus, smallpox it
too toxic and lethal to work with
What are pocks/pox?
Blister-like lesions on the skin
What are the two forms of poxviruses that can be formed?
1. Mature Virus
2. Extracellular Virus
How is infection different in each virion type? (tissue-to-tissue in host vs one host to another host)
Mature – spread from one host to another
Extracellular – cell to cell/tissue to tissue spread in host
Which survives better in the environment?
Mature virus
What do the viruses bind to (receptors)? How does this affect host range for poxviruses?
Both bind to host glycosaminoglycans which are ubiquitous on mammalian cells
- Why virus has wide host range
Entry mechanism – is there a difference between the two forms?
Genome: What is different about the terminal ends of the genome?
Terminal ends (10 kbp) contain inverted repeats
- Last 4 kbp have no genes
o 200 short tandem repeats, hairpin structure last 100 bp
What feature(s) is/are located at the very end?
200 short tandem repeats, hairpin structure last 100 bp
Where are the conserved genes (all poxviruses) located? What types of functions do they have?
Conserved genes are located in the center of the genome
Involved with essential functions
- Replication, transcription (house keeping genes)
Where are the virus-specific genes located? What types of functions do they have?
Genes at the end are virus-specific
Involved with host binding, pathogenesis
How are poxvirus genes different from genes in eukaryotic cells? Why is this so?
Genes do not have introns or splicing RNA
This is odd because replicates in cytoplasm, enzymes that do splicing are found in the nucleus
Chapter 26 Review Guide
General characteristics of Poxviruses
General size, shape, capsid structure/type, genome (number, if applicable, and type)
Size – large
Shape – large ovoid to brick shape structure
Capsid – NO CAPSID
Genome – dsDNA, 150-250 kb
In terms of capsid structure, how are poxviruses different than other animal viruses we covered?
They do not have a capsid
What disease does variola virus cause?
Smallpox, humans only
What disease does vaccina virus cause? Why important in human health history?
Variant of cowpox, most of what we know about poxviruses is from studying vaccina virus, smallpox it
too toxic and lethal to work with
What are pocks/pox?
Blister-like lesions on the skin
What are the two forms of poxviruses that can be formed?
1. Mature Virus
2. Extracellular Virus
How is infection different in each virion type? (tissue-to-tissue in host vs one host to another host)
Mature – spread from one host to another
Extracellular – cell to cell/tissue to tissue spread in host
Which survives better in the environment?
Mature virus
What do the viruses bind to (receptors)? How does this affect host range for poxviruses?
Both bind to host glycosaminoglycans which are ubiquitous on mammalian cells
- Why virus has wide host range
Entry mechanism – is there a difference between the two forms?
Genome: What is different about the terminal ends of the genome?
Terminal ends (10 kbp) contain inverted repeats
- Last 4 kbp have no genes
o 200 short tandem repeats, hairpin structure last 100 bp
What feature(s) is/are located at the very end?
200 short tandem repeats, hairpin structure last 100 bp
Where are the conserved genes (all poxviruses) located? What types of functions do they have?
Conserved genes are located in the center of the genome
Involved with essential functions
- Replication, transcription (house keeping genes)
Where are the virus-specific genes located? What types of functions do they have?
Genes at the end are virus-specific
Involved with host binding, pathogenesis
How are poxvirus genes different from genes in eukaryotic cells? Why is this so?
Genes do not have introns or splicing RNA
This is odd because replicates in cytoplasm, enzymes that do splicing are found in the nucleus
