bacterial conjugation take place in bacteria

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