Bacterial Transduction – Horizontal Gene Transfer Part – III
Bacterial transduction is a horizontal gene transfer method in bacteria which is mediated by bacteriophage or bacterial viruses.
It is the transfer of bacterial genes by viruses and this transfer is the result of an error made during the viral gene packaging.
It can be of two types:
- Generalized transduction: It occurs during the lytic cycle (after infection of bacteria, bacteriophage take control of the host machinery and forces it to produce copies of viral components) of phages and it is called so because in this type of transduction, random fragment of degraded bacterial chromosome (genes) are packed instead of viral genes. These resulting phages are called generalized transducing particle or phages which are carrier of genetic information from donor bacteria to another cell.
- Specialized transduction: It occurs during the lysogenic cycle (after infection of bacteria, viral genome does not take control of its host. Instead the viral genome remains within the host cell and reproduces along with the bacterial chromosome) of phages and it is called so because in this type of transduction, a specific portion of bacterial genome gets packed due to improper excision. Therefore, along with the phage genome portion of bacterial chromosome is packed in the phage particles. When these resulting phages infect new bacteria, the previously carried bacterial genes may get incorporated into the host.
Understand the other two methods of horizontal gene transfer in bacteria here – Conjugation and Transformation.