AAT Bioquest

What happens in the lysogenic cycle?

Posted January 26, 2023


The lysogenic cycle is a mechanism by which a virus can replicate its DNA using a host cell. The DNA is only replicated in this cycle. It is not translated into proteins. The lysogenic cycle occurs over 5 main stages. 

  1. The viral DNA enters the host cell, exposing the host organism to the virus, and initiating the lysogenic cycle. 
  2. The host cell’s proteins that are responsible for DNA replication, read and then replicate the viral DNA. By the end of this stage, the virus has already attached itself to the host, created a hole in its cell membrane, and injected its DNA. 
  3. Viral DNA continues using the host cell’s machinery to replicate.  In this cycle, DNA replication occurs only when the host cell is replicating its own DNA. 
  4. The lysogenic cycle may continue at this point or the virus may switch to the lytic cycle in order to produce many more copies of DNA and protein covers or capsids. 
  5. The capsids are released into the environment, where they are able to infect new host cells, triggering a new lysogenic cycle. If the host cell is weak and in danger of dying, the virus may enter straight into the lytic cycle in an attempt to keep the host cell alive.
Additional resources

Low Host Abundance and High Temperature Determine Switching from Lytic to Lysogenic Cycles in Planktonic Microbial Communities in a Tropical Sea (Red Sea)

Covidyte™ EN450

MycoLight™ Live Bacteria Fluorescence Imaging Kit