Phage

[Qphage]

Does prophage in lysogeny get inactivated?
Prophage is a potent phage produced during lysogenic cycle of bacphages.
Does potential of a prophage to be a virulent phage get inactivated?

[david23]

lysogenic and lytic cycles are competing with each other depending on the various presence of activator and repressor proteins. You want more in detail? I have to check up my references for the exact names of the proteins.

[MrMistery]

Don't bother. The system is names the Cro/CI system. The two genes, Cro and CI, compete with each other, as one protein inhibits the transcription of the other. When high levels of Cro protein are present, the phage enters the lytic cycle. When high levels of CI protein are present, the phage enters the lysogenic cycle.

Note: I learned these for the lambda phage. Don't know if they go for ALL phages(i am guessing not). But this is a really common example.

[david23]

So far I think it's safe to say that the Cro/Cl system is in the lambda phage families.