Transduction

Transduction is a mechanism of genetic recombination that occurs in bacteria where the incorporation of host cell DNA and the bacteriophage genetic material, which results in the formation of recombinant DNA. Bacterial transduction occurs by the means of generalized and specialized transduction.

In generalized type, any of the genes can be transduced of the host cell whereas only special genes are transduced in specialized type. Transduction was given by scientists in 1952 by Norton Zinder and Joshua Lederberg. The process of transduction was first studied in the bacterium Salmonella.

Content: Transduction

  1. Definition
  2. Types
  3. Conclusion

Definition of Transduction

Transduction is the gene transfer mechanism where the genetic material is transferred from one bacterial cell to the next bacterial cell by the “Bacteriophages” as the vectors. The insertion of foreign DNA by the bacteriophages from a donor cell to a recipient cell also defines the process of transduction.

Types

The transduction in bacteria occurs in two ways either through a lytic or lysogenic cycle:

Types of transduction

  • Generalized transduction
  • Specialized transduction

Generalized Transduction

It is the kind of Lytic phase where the bacteriophage only carries the pure bacterial DNA, not the phage DNA and this pure bacterial gene is inserted into the recipient cell.

Process: It includes the following steps

generalized transduction

  1. First, the bacteriophage attack the bacterial cell which will represent as the “Donor cell”.
  2. Then, the bacteriophage injects its genetic material that will penetrate into the bacterial chromosome.
  3. The phage DNA then controls the host cell machinery. This cause the degradation of the bacterial chromosomal DNA which leads to the small fragments of the genetic material.
  4. Then replication of phage DNA occurs. At the time of packaging, the genetic material of the bacterial DNA accidentally gets into the bacteriophages which refer as “False packaging”.
  5. Then the biosynthesis of Bacteriophages occurs and after that, the phages get assembled and cause lysis of the donor cell.
  6. The bacteriophages then attack the other bacterial cell ( Recipient cell ) and will penetrate the phage DNA into it.
  7. The phage DNA will incorporate in the recipient’s DNA leads to the formation of “Recombinant cell”.

Specialized Transduction

It is the kind of Lysogenic phase where a gene transfers from a donor cell to the recipient cell by the bacteriophage which not carries the pure bacterial DNA i.e. it contains both the bacterial DNA and the phage DNA.

Process: It includes the following steps

specialized transduction

  1. First, the bacteriophage attack the bacterial cell which will represent as “Donor cell”.
  2. Then, the genetic material of the bacteriophage will penetrate into the bacterial chromosome.
  3. The phage DNA will induce bacterial DNA and starts the replication cycle.
  4. The phage DNA then control over the cell machinery of the bacteria. This cause the assembly of the bacteriophages which carries both phage and Donor’s DNA.
  5. After that, there is the induction under a UV-light which cause cell lysis and the release of Lysogens.
  6. Then, the bacteriophages attack the other bacterial cell will represent as “Recipient cell”. This bacteriophage will penetrate the prophage DNA into the recipient cell.
  7. The phage DNA and the Donor cell DNA will incorporate in the recipient’s DNA leads to the formation of “Recombinant cell”.

Conclusion

Therefore, the transduction is the molecular biological technique which helps in gene alternation or gene recombination. Transduction is generally the process of introduction of a foreign gene into the host cell genome by the bacteriophages.

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