BRAINCAKEDNA Virus Latency
Latency is a state in which a virus is inside a host cell but is not replicating and is not making new virus particles. The viral genome is kept in the cell and is passed on when the cell divides. In bacteriophages this is called the lysogenic pathway.
Lambda (λ) phage is the classic example. After injecting its DNA into E. coli, the linear phage DNA forms a circle. In the lysogenic pathway it is then inserted into the bacterial chromosome at a specific site, where it is called a prophage. A viral repressor protein switches off the genes needed for lytic replication. Every time the bacterium divides, the prophage is copied along with the bacterial DNA, so all the daughter cells carry it. The host is not harmed and may even gain resistance to infection by similar phages.
Sign in free to see the rest of this lesson, the R.E.C.I.P.E. recall steps and the quiz
BrainCake is free. Make an account in seconds and pick up where this page stops.
More in Prokaryotic Cells
- RNA Viruses
- RNA Retroviruses
- Viral Reproduction
- Virus Life Cycle
- DNA Virus Lytic Pathway
- RNA Virus Replication
- Positive ssRNA Viruses
- Negative ssRNA Viruses
All 31 lessons in Prokaryotic Cells · All Edexcel AS-level Biology topics