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Colossians 1:16, 17 16 For by him were all things created, that are in heaven, and that are in earth, visible and invisible, whether they be thrones, or dominions, or principalities, or powers: all things were created by him, and for him:
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Colossians 1:16, 17 16 For by him were all things created, that are in heaven, and that are in earth, visible and invisible, whether they be thrones, or dominions, or principalities, or powers: all things were created by him, and for him: 17 And he is before all things, and by him all things consist.
Bacterial Genetics Timothy G. Standish, Ph. D.
Cell Wall Cell Membrane Cytoplasm Origin of Replication Chromosome Termination of Replication Bacteria Have Circular Chromosomes
Replication goes in both directions Original Chromosome Start of replication Theta (q) structure Mid replication End of replication Two chromosomes Replication
Genetic Recombination • If bacteria were incapable of genetic recombination, all members of a given species would be clones with differences arising only due to mutations in different lines • If bacteria could not share genetic information as other organisms do in sexual reproduction, there would be vastly less opportunity to adapt to different environments • As it turns out, bacteria are notorious for their ability to adapt, thus it is not surprising that elegant mechanisms exist for sharing genetic information
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
A B C A B C 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 Transformation with A and C is unlikely
F plasmid F- bacteria F plasmid 2 Conjugation F+ bacteria Mating Bridge
F plasmid F+ bacteria F- bacteria F plasmid 2 Conjugation Mating Bridge
F plasmid F+ bacteria F- bacteria F plasmid 2 Conjugation Mating Bridge
F plasmid F+ bacteria F- bacteria 2 Conjugation Mating Bridge F plasmid
F plasmid F+ bacteria F- bacteria 2 Conjugation Mating Bridge F plasmid F plasmid
F plasmid Integration Hfr cell F+ bacteria F- bacteria Transfer of genetic material Hfr Recombination
F plasmid Integration Hfr cell F+ bacteria F- bacteria Crossing over Hfr Recombination Interruption of conjugation Transfer of genetic material
F plasmid Integration Hfr cell F+ bacteria F- bacteria Hfr Recombination Recombinant Bacteria
Destruction of the bacteria’s DNA Infection Replication of the viral genome Production of viral parts Packaging Lysis 3 TransductionGeneralized
Temperate Phage Part of the bacteria’s DNA Replication of the viral genome Production of viral parts Packaging Lysis 3 TransductionSpecialized
The End
