Types of Transduction, Typhimurium, Salmonella strain, Bacterial genes, Chromosomes, Phage Genome

Types of Transduction

	Types of Transduction In experiments performed by Zinder and Lederberg, with phage P22 and S.typhimurium L22, it was found that the phage can carry any part of the bacterial DNA and transfer this to another Salmonella strain. The new bacterial DNA thus introduced into the recipient strains was subsequently integrated into the recipient cell DNA.
This ability of the bacteriophage to carry with its genetic material any region of the bacterial DNA is now known as "generalized transduction" (unrestricted transduction). As opposed to this, there are bacterial phages such as the lambda phage (λ) of E. coli which can carry only a specific region of the bacterial DNA to, a recipient and this is called as "Specialised transduction" (restricted transduction). The technique of specialized transduction has been extensively used in recent years to determine the fine structure of bacterial genes.
Phage preparations obtained by the induction of lysogenic cultures possess transducing properties. However, phages that emerge from the lytic infection are inert. The generation of transducing phage involves a kind of recombination between the bacterial and prophage chromosomes and during later release, a part of the bacterial chromosome is exchanged for a part of the phage genome