Genetic Recombination in Bacteria

1
(No Transcript)
2
Bacteria Genetics
3
Introduction

• Chromosome (bacteria are haploid in other
  words, they have a single chromosome)
• Mutations (change in the base sequence of DNA)
• Extrachromosomal genetic material
• Plasmid
• Transposons
• Genetic recombination Transfer of DNA from one
  bacterium to another

4
Introduction

• Changes in the genome can occur by two processes
• Mutations
• Genetic recombination
• The changes in the genome is of considerable
  importance in terms of bacterial virulence and
  drug resistance

5

• Genetic Recombination
• The transfer of DNA from one organism to another
  with subsequent integration into the DNA of the
  recipient

6
Genetic Recombination

• Three mechanisms
• Transformation
• Transduction
• Conjugation

7
Transformation

• Definition
• Genetic recombination in which a DNA fragment
  from a dead degraded bacterium enter a competent
  recipient bacterium and is exchanged for a piece
  of DNA of the recipient
• Mechanism
• Dead/donor bacterium source of DNA
• DNA fragment from the dead donor bacterium binds
  to DNA binding protein on the cell wall of the
  competent living recipient bacterium

8
Transformation
9
Transduction

• Definitions
• Transduction - Genetic recombination in which a
  DNA fragment is transferred from one bacterium to
  another by a bacteriophage
• Bacteriophage - A virus that only infects
  bacteria

horiz gene transfer-, Transposons--robert
10
Transduction
11
Conjugation

• Genetic recombination in which there is a
  transfer of DNA from a living donor bacterium to
  a recipient bacterium, often thorugh a sex pilus.
• Pilus - A tubular protein structure extending
  from a bacterial surface used for attachment to
  environmental surfaces or cells. A sex pilus is
  involved in bacterial conjugation.

12
Plasmid Conjugation
13
(No Transcript)
14
R Plasmid Conjugation