Lecture on Gene Transfer in Bacteria

Introduction

Horizontal Gene Transfer vs. Vertical Gene Transfer
- Horizontal gene transfer enables bacteria to evolve within their lifetime.
- Vertical gene transfer involves passing genes through reproduction (parent to offspring).

Example: Human reproduction where genes are mixed from parents (e.g., speaker and wife) to create offspring (e.g., their son Oliver).
Important for adaptation and evolution across generations.

Allows bacteria to evolve by acquiring new traits during their lifetime.
Key for developing resistance to antibiotics, acquiring new toxins, and adapting to new food sources.

Transformation
- Transfer of naked DNA from one organism to another in solution.
- Example: E.coli acquiring genes for antibiotic resistance or toxins by interacting with DNA in their environment.
- Concept: Bacteria assimilate free-floating DNA they encounter (akin to swimming in a pool of DNA).
Transduction
- Genetic material transferred via a bacteriophage (phage).
- Phages infect bacteria, incorporate bacterial DNA, and transfer it to other bacteria.
- Further details to be covered in future in-depth lectures.
Conjugation
- Physical transfer of DNA between bacteria through a sex pilus or mating bridge.
- Involves transfer of plasmids, allowing bacteria to share advantageous traits.
- Example: Bacteria under a biofilm sharing resistance factors.
Transposons (Jumping Genes)
- Discovered by Barbara McClintock, Nobel Prize in 1983.
- Genes that can move within a chromosome or between chromosomes.
- Importance in antibiotic resistance: Can jump to plasmids and transfer to other organisms.

Horizontal gene transfer mechanisms are crucial for bacterial adaptation and evolution.
These processes enable bacteria to acquire and disseminate traits that can impact human health (e.g., antibiotic resistance).

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