Question

What is transduction?

Answer 1

Hint:- Various multicellular or unicellular bacteria have evolved the mechanism of genetic transfer from parent to offspring and these mechanisms are collectively known as Horizontal Gene transfer. Horizontal gene transfer plays an important role in the evolution of organisms. There are several mechanisms employed by the organisms for horizontal gene transfer which include Transformation, Transduction, and Bacterial Conjugation.

Complete step-by-step solution:- Transduction is a process involving the introduction of foreign DNA material into the cell by a viral vector. Examples include the viral transfer of DNA from one bacteria to another bacteria. Transduction was discovered by Zinder and Lederberg in Salmonella. Transduction, unlike Conjugation, doesn't require direct contact between the cell donating the DNA and the cell receiving the DNA.
Transduction can occur through the lytic cycle or the lysogenic cycle. In the lytic cycle, viruses infect bacterial cells to synthesize new viral particles. The virus uses host machinery for replication, transcription, and translation and the new viral particles are released by the lysis of the host. In the lysogenic cycle, the viral genetic material gets integrated into the host chromosome which is called Prophage where it is dormant for a while. After induction of prophage, mainly by UV light, the phage genome gets separated from the bacterial chromosome and then initiates the lytic cycle.
Transduction can be of the following types:
a) Generalized Transduction which includes random packaging of bacterial DNA into phage. It occurs in both lytic and lysogenic cycles during the lytic stage.
b) Specialized Transduction involves the transfer of a restricted set of bacterial genes to other bacteria. It occurs when prophage is excised during a lysogenic cycle.
c) Lateral Transduction involves the transfer of long fragments of DNA from one bacterium to another. This only occurs in Staphylococcus aureus.

Note:-
Molecular biologists use transduction as a tool to introduce foreign genes into the host's cell genome. It is also used in correcting genetic errors in a technique called gene therapy. The transduction efficiency can be increased by using certain enhancers such as Polybrene, Protamine sulphate, Retronectin, and DEAE dextran.