Bacterial conjugation is a form of horizontal gene transfer that requires physical contact between bacteria. During conjugation, genetic material is transferred from a "donor" bacteria to a "recipient" bacteria via a pilus. The F plasmid contains genes necessary for conjugation and is present in the donor cell. Conjugation results in the donor cell transferring a segment of its DNA to the recipient cell, integrating it into the recipient's genome and allowing for genetic recombination between the two bacterial cells. This transfer of antibiotic resistance and other genes between bacteria through conjugation contributes to the spread of multidrug resistance.

1. Bacterial
Conjugation
Roll no- 1626011

2. Content
• Introduction
• Genetic recombination
• Transduction
• Transformation
• Conjugation
• Who Is Donor
• F plasmid
• Terminology

3. Introduction
• Bacterial conjugation was first discovered by LEDERBERG & TATUM In
1946
• In E.coli k12 strains

4. Genetic recombination
• Genetic variability – ESSENTIAL!!!
• Survival of the species
• Diploid Eukaryotes
• Crossing over
• Meiosis
• Haploid Prokaryotes
• Transduction
• Transformation
• Conjugation

5. Transduction
• Genetic material exchanged via Viruses
• E.g. bacteriophage lambda
• No physical contact b/w bacteria
• Promotes drug resistance
• Horizontal gene transfer

6. Transformation
• Acquisition of exogenous DNA fragments from environment
• E.g. Plasmids
• Antibiotic resistance
• Pesticide resistance in crops
• E.g. Agrobacterium tumefaciens
• Horizontal gene transfer

7. Conjugation
• Exchange of genetic material b/w bacteria
• Physical contact required
• DNA exchanged via Pilli
• Drug resistance!!
• Horizontal Gene Transfer

8. Conjugation
Bacteria A Bacteria B
Transfer of genetic material from Bacteria A to Bacteria B by matting or
contact is called conjugation

9. Who Is Donor
F Plasmid Absent
Donor recipient
F+ F-
Male cell Female cell

10. F plasmid
• Fertility factor
• Sex factor
• Transfer factor

11. Reversible
F + Hfr

12. Terminology
The Donor:- F+ , Fertility factor - Contains genetic material for gene
exchange “male” cell
The Recipient:- F- No fertility factor Receives genetic material
“Female” cell
The Conjugate:- HFR -High frequency recombinant , Resulting
genetic recombinant ,Transfers entire genomic DNA when mixed with F-
cells

13. 1. Cell – Cell Contact
Formation of “sex pilus” or F-bridge between cells

14. 2. Mobilization
• Target DNA is replicated in F+
• Genetic transfer of ssDNA to F-

15. 3. DNA Synthesis
• Complementary strands of DNA are replicated in both F- and F+
• Target DNA is incorporated into F- genome

16. 4. Separation
• Cells separate
• Form two F+ cells with completed recombinant plasmids
• Both serve as donor cells for further conjugation

17. Reference
• www.google.com
• www.wikipidia.com
• Basic Biotechnology by- Fr. Dr. S. Lgnacimuthu
• Fundamentals of Microbiology