Zygotic induction occurs when a bacterial cell carrying the silenced DNA of a bacterial virus in its chromosome transfers the viral DNA along with its own DNA to another bacterial cell lacking the virus, causing the recipient of the DNA to break open.
In the donor cell, arepressor proteinencoded by the prophage (viral DNA) keeps the viral genes turned off so that virus is not produced.When DNA is transferred to the recipient cell by conjugation, the viral genes in the transferred DNA are immediately turned on because the recipient cell lacks the repressor.
As a result, many viruses are made in the recipient cell, andlysiseventually occurs to release the new virus.
Zygotic induction was discovered by Élie Wollman and François Jacob in 1954.
Historically, zygotic induction provided insight into the nature ofbacterial conjugation. It also contributed to the development of the earlyrepression model of gene regulationthat explained how the lac operon and λ bacteriophage genes are negatively regulated.
