Mutation Rates in E' coli MC4100 and Hfq

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Mutation Rates in E. coli MC4100 and Hfq-

• Biomath Research - Summer 08
• Glen Hamman
• Jan Varada

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Goals

• To determine the effect of the Hfq protein in the
  deletion of quadruplex-forming DNA sequences.
• If the Hfq protein is involved in removing the
  quadruplex structures, hfq cells with the
  protein should revert slower than hfq- cells
  without the protein.

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Approach

• Insert a DNA quadruplex-forming structure in the
  TET gene of the pBR325 plasmid.
• Do a transformation into the E. coli HB101
  strain, and plate to select AMP resistant
  colonies which have the plasmid.
• Patch in grid in AMP and TET and select those
  that do not grow in TET because they have the
  quadruplex DNA structure.
• Select those colonies, purify DNA and do
  transformations into the MC4100 and Hfq- strains
  and compare reversion rates.

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DNA quadruplex structure
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pBR325 plasmid vector
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Results so far
AMP plate
TET plate
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Results so far
CAP plate
AMP plate
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Results so far
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Results so far
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To do

• Purify DNA from viable colonies and do
  transformations into the MC4100 and Hfq- strains.
• Calculate the reversion frequency and complete
  the mutation rate experiment.
• Follow up on the mathematical models describing
  the mutation behavior and compare predictions
  with experimental data.