BOLOGY 107 Lecture 33Outline of Last Lecture I. Bacteria and Archaeaa. Two of the three domains of lifeb. Cell featuresc. Cell organizationd. Prokaryotic cell divisionRapid adaptation Outline of Current Lecture II. Bacteria and Archaeaa. Genetic transfer in bacteriab. Antibiotic resistanceCurrent LectureBacteria and Archaea1) Genetic transfer in bacteriaa) Exchange portions of genomeb) Allows for genetic recombinationc) Three typesi) Transduction (1) Virus mediated DNA transfer(2) No direct contact between cells needed(3) Once a virus infects a cell, it reproduces its own DNA as it breaks the host cell’s DNA. Some of the host DNA can be packaged in the virus, then be injected into another host cellii) Conjugation (1) Transfer from one cell to another(2) Requires a sex pilus (specialized fimbria)(3) A cell must contain the “F factor”(a) DNA coding for conjugation(b) If on plasmid, the cell is F+(c) If in genome, it is and Hfr cell (high frequency of recombination)(4) F factor cell serves as donor(5) F+ conjugation(a) Sex pilus forms(b) One strand of the plasmid is transferred to the recipient These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.(i) “Rolling circle” replication to reproduce plasmid in donor and send one strand to the recipient(c) DNA is replicated and circularized in the recipient(i) Recipient cell is now F+(6) Hfr conjugation(a) Process happens the same until the rolling circle replication(b) Amount of DNA transferred is time dependant(i) Timed process used to map genome of E. coli in minutes rather than Morgans(c) Some transferred DNA is incorporated, some is degraded(d) The recipient cell is never made F+(7) Transformation (a) Bacteria pick up DNA from the environment(b) One cell dies, another scavenges the DNA pieces(c) Usually uses phagocytosis to break the DNA for its own replication(d) Sometimes incorporated into genome(e) Can be cross-species(i) Japanese have bacteria in their gut to break down kelp from DNA out of dead aquatic bacteria2) Antibiotic resistancea) Antibiotics produced by fungi and some bacteriai) Can be chemically synthesized b) Kills bacteria by disrupting the cell wall, gene expression, or other targetsc) Mutations (including gene transfer) can allow bacteria to:i) Reduce drug uptakeii) Transport the drug out of the celliii) Inactivate the drug by metabolizing it or modifying itiv) Alter or amplify the
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