BACTERIAL TRANSDUCTION PRESENTED BY SAIRA FATIMA ROLL NO:31 MSc 4 [2018-2020] Department of MicroBiology & Molecular Genetics University of the Punjab Lahore, Pakistan

1. BACTERIAL
TRANSDUCTION
PRESENTED BY SAIRA FATIMA
ROLL NO:31
MSC 4 [2018-2020]
Department of MicroBiology & Molecular Genetics
University of the Punjab
Lahore, Pakistan

2. DEFINATION
• The transfer of genetic material from one cell to
another cell by a bacteriophage is called
Transduction .
• Transduction has been found to occur in variety
of prokaryotes , including certain species of
Bacteria : Escherichia , Pseudomonas , Salmonella
, Staphylococcus , etc.
• The bacteriophage containing the bacterial DNA
is called transduced DNA .

3. DISCOVERY
• Transduction was discovered by Zinder
and Lederberg while searching for
conjugation in salmonella typhimurium .
• Lederberg-Zinder experiment - After
placing two auxotrophic strain of
Salmonella on opposite side of the U-
tube, the researches recovered
prototrophs from the side with the LA-22
strain, but not from the containing the LA-
2 strain.
• These initial observations led to the
discovery of the phenomenon called
transduction

4. U – TUBE EXPERIMENT

5. BACTERIOPHAGE
• A bacteriophage is a virus that infects
and replicate within a bacterium .

6. TYPES OF BACTERIOPHAGE
• VIRULENT : Capable of causing infection and eventually
destruction and death of the bacterial cell . These follow
LYTIC CYCLE . Example : T4 host E.coli .
• TEMPERATE: Does not cause destruptic infection instead
phage DNA incorporated into bacterial DNA and replicate
(LYSOGENIC)and after some cycle become virulent cause
lysis. Example : lamda phage .

7. TYPES OF TRANSDUCTION
There are TWO types of transduction:
1. Generalized transduction • A DNA
fragment is transferred from one bacterium
to another by a lytic bacteriophage(virulent)
which carrying donor bacterial DNA due to
an error .
2. Specialized transduction • A DNA
fragment is transferred from one bacterium
to another by a temperate bacteriophage
which carrying donor DNA along with
phage genome due to an error .In this a
phage insert a genome at specific site.

9. STEPS OF GENERALIZED TRANSDUCTION
• A lytic bacteriophage infect a susceptible
bacterium .
• The phage genome enters into the bacterium .
The genome directs a bacterium’s metabolic
machinery to manufacture bacteriophage
components and enzyme .
• Occasionaly , a bacterial genome get into a
phage coat by mistake and the bacteriophage
released .
• When this phage having bacterial DNA infect
another bacterium , the previous bacterial DNA
incorporated into new bacterial genome forming
recombinant DNA .

11. STEPS OF SPECIALIZED TRANSDUCTION
1. A temperate bacteriophage infect a susceptible
bacterium and inserts its genome into bacterium .
2. The DNA of a bacteriophage, incorporated into
the genome of a bacterium . It is called
PROPHAGE . 3
3. .Occasionally during spontaneous induction , a
small piece of the donor bacterial DNA is picked
up as part of the phage genome .
4. As the bacteriophage replicates , the segment of
bacterial genome also replicates along with
phage genome .
5. When this phage infect another bacterium , the
donor DNA along with phage genome inserted
into a recipient bacterial genome forming
recombinant DNA .

12. ABORTIVE TRANSDUCTION
• Transduction in which the DNA fragment
from the donor bacterium(transduced DNA)
is not integrated in the genome of the
recipient bacterium and when the latter
divides, is transmitted to only one of the
daughter cells.

13. SIGNIFICANCE OF TRANSDUCTION
• It transfer genetic material from one cell to another
and alter genetic characteristic .
• For Example , In specialized transduction, a cell
lacking ability to metabolize galactose could
acquired ability .
• It shows evolutionary relationship between the
prophage and host bacterial cell.
• Prophage can exist in a cell for a long period
suggest a possible mechanism for viral origin of
cancer . • It provides a way to study the gene
linkage .

14. THANK YOU