The process though which bacterial transduction is carried out to bring changes in two different bacterias naturally.

1. Transduction On Bacteria
PRESENTED BY : SUSMITA KUMARI & SWETA PAL
FROM : GURU NANAK INSTITUTE OF PHARMACEUTICAL
SCIENCE & TECHNOLOGY

2. INTRODUCTION
 Transduction is a mode of bacterial gene transfer.
 Transfer takes place between bacteriophages and bacteria
before cell lysis.
 It is a frequent mode of horizontal gene transfer in nature
,mediated by viruses.
 It occurs in two patterns:
-Generalized Transduction
-Specialized Transduction

3. What makes a transducing phage?
 For a phage to be transducing it must have the following
characteristics:-
-Must not degrade the host DNA completely after
infection.
-No host DNA will be available to be packaged into
phage head when packaging begins.
-DNA must not lacks packaging sites. For e.g - pac or
cos sites etc.

4. Generalized Transduction
 Discovered by Joshua Lederberg and Norton Zinder in 1951.
 Any region of the bacterial DNA can be transferred from one
bacterium to another.
 Occurs by wrong packaging of DNA between the phage and the
bacterial DNA before lysis.
 Lytic cycle was performed in bacteria Salmonella typhimurium
and the phage P22.

5. Mechanism of Generalized Transduction:

6. Specialized Transduction
 Also called restricted transduction.
 Discovered by Lederberg & his students in phage lamba.
 The transducing particle carries only specific portions of the
bacterial genome.
 Occurs by causing an error in the lysogenic phase.
 The best-studied example is the E. coli phage lambda.

7. Mechanism of Specialized Transduction:

8. Limitation of Transduction:
 Transduction occurs very rearly because of the following
reasons:
-Mistaken packaging of host DNA is itself very rare.
-Transduced DNA must survive in the recipient cell
to form stable transductant.
 Each of these step has a limited success to undergo
transduction naturally.

9. Conclusion
Transduction is the transfer of bacterial genes by viruses.
Bacterial genes are incorporated into a phage capsid because of
errors made during the virus life cycle. The virus containing these
genes then injects them into another bacterium, completing the
transfer. It involves the lytic and lysogenic cycle for the DNA
transfer by its two form i.e the generalized & specialized
transduction.

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