Bacterial Genetics

Bacteria Have Circular Chromosomes Cell Wall Cytoplasm Cell Membrane Chromosome Origin of Replication Termination of Replication

Replication Replication goes in both directions Original Chromosome Start of replication Theta (q) structure End of replication Two chromosomes Mid replication

Binary Fission

Ways Bacteria Exchange Genetic Material Transformation - Bacteria take up DNA from their environment and incorporate it into their genome (i.e. the Griffith experiment) Conjugation - The direct transfer of DNA by bacteria usually via plasmids Transduction - Movement of DNA between bacteria by viruses

1 Transformation Crossing over Insertion

1 Transformation

1 Transformation

1 Transformation

1 Transformation

1 Transformation

Crossover Frequency Following binary fission, one daughter cell will have the recombinant strand and thus have a recombinant chromosome Mapping bacterial genes following transformation is not significantly different from eykaryotic mapping. The closer two genes are to one another, the lower the probability of a crossover event between them and thus the higher the probability that they will be co-transformed A B C Transformation with A and C is unlikely A B C

2 Conjugation F plasmid F plasmid F+ bacteria F- bacteria Mating Bridge F- bacteria F plasmid

2 Conjugation F plasmid F plasmid F+ bacteria F- bacteria Mating Bridge F plasmid

2 Conjugation F plasmid F plasmid F+ bacteria F- bacteria Mating Bridge F plasmid

2 Conjugation F plasmid F plasmid F+ bacteria F- bacteria Mating Bridge F plasmid

2 Conjugation F plasmid F plasmid F plasmid F+ bacteria F- bacteria Mating Bridge F plasmid F plasmid

Transfer of genetic material Hfr Recombination F+ bacteria F plasmid Integration Hfr cell Transfer of genetic material F- bacteria

Transfer of genetic material Hfr Recombination F+ bacteria F plasmid Integration Hfr cell Interruption of conjugation F- bacteria Crossing over Transfer of genetic material

Hfr Recombination F+ bacteria F plasmid Integration Hfr cell Recombinant Bacteria

3 Transduction Generalized Destruction of the bacteria’s DNA Infection Replication of the viral genome Production of viral parts Packaging Lysis

3 Transduction Specialized Temperate Phage Part of the bacteria’s DNA Replication of the viral genome Production of viral parts Packaging Lysis