HIV Evolution Flashcards
1
Q
HIV lifecycle
A
- virus attaches to cell surface
- core enters cell and RNA converted to DNA
- DNA enters nucleus
- DNA integrates into host cell genome
- transcription and exit of RNA copies from the nucleus
- translation of new virus proteins
- movement of RNA to cell surface
- congregation of RNA and virus components at the cell surface
- new virus particle buds from cell
2
Q
Advantages of small viruses
A
- reproduce faster
- more can fit in infected cell
3
Q
Replication rate for humans
A
0.3 per cycle
4
Q
Replication rate of HIV
A
5-0.3 per cycle
5
Q
Why is HIV’s mutation rate variable?
A
- RT is error prone and can’t proofread
- APOBEC3G edits C to U
- VIf prevents entry of APOBEC3G into virion
- Vpr recruits UDG into virion
6
Q
Define quasispecies
A
A group of viruses related by a similar mutation or mutations, competing within a highly mutagenic environment
7
Q
4 types of mutant
A
- neutral
- harmful
- conditionally useful
- useful
8
Q
When and how does recombination occur?
A
- switching of RT between two different templates
- packaging of two separate genomes into every virus particle
- frequent infection of individual cells with more than one virus particle encourage recombination
