Transduction (genetics)

Transduction is the process by which foreign DNA is introduced into a cell by a virus or viral vector. An example is the viral transfer of DNA from one bacterium to another and hence an example of horizontal gene transfer. Transduction does not require physical contact between the cell donating the DNA and the cell receiving the DNA (which occurs in conjugation), and it is DNase resistant (transformation is susceptible to DNase). Transduction is a common tool used by molecular biologists to stably introduce a foreign gene into a host cell's genome (both bacterial and mammalian cells).

Discovery (bacterial transduction)

Transduction was discovered in Salmonella by Norton Zinder and Joshua Lederberg at the University of Wisconsin–Madison in 1952.

In the lytic and lysogenic cycles

Transduction happens through either the lytic cycle or the lysogenic cycle.

When bacteriophages (viruses that infect bacteria) that are lytic infect bacterial cells, they harness the replicational, transcriptional, and translation machinery of the host bacterial cell to make new viral particles (virions). The new phage particles are then released by lysis of the host. In the lysogenic cycle, the phage chromosome is integrated as a prophage into the bacterial chromosome, where it can stay dormant for extended periods of time. If the prophage is induced (by UV light for example), the phage genome is excised from the bacterial chromosome and initiates the lytic cycle, which culminates in lysis of the cell and the release of phage particles.