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.
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 Revisited
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) Transduction - Movement of DNA between bacteria by viruses Conjugation - The direct transfer of DNA by bacteria usually via plasmids
Transformation Crossing over Insertion
Transduction Generalized Destruction of the bacteria’s DNA Infection Replication of the viral genome Production of viral parts Packaging Lysis
Transduction Specialized Temperate Phage Part of the bacteria’s DNA Replication of the viral genome Production of viral parts Packaging Lysis
Conjugation F plasmid F+ bacteria Mating Bridge F- bacteria
Conjugation F plasmid F+ bacteria Original F+ bacteria F- bacteria New Mating Bridge Original F+ bacteria F- bacteria New F+ bacteria
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
Transcription And Translation In Prokaryotes 3’ 5’ 5’ mRNA RNA Pol. Ribosome Ribosome
The End