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Homework Help: E.coli with minimal media problem, HELP!

  1. Jun 30, 2007 #1
    1. The problem statement, all variables and given/known data
    in the picture/attached file

    2. Relevant equations
    no equations necessary

    3. The attempt at a solution
    don't know how to start it off. I know the E.coli strain can't make the 5 compounds and the colonies present indicate which gene it's missing but I don't know how to determine the gene order from the data.

    can someone give me a hint, please?

  2. jcsd
  3. Jun 30, 2007 #2


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    Can you post the a link to the picture or explained the data?

    The attached file is not present.
  4. Jul 1, 2007 #3
    sorry about that, here's the file.

    Attached Files:

  5. Jul 1, 2007 #4


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    That's classical way to do genetics.

    The solution is based on recombination and the chance of unique, double, triple, quadruple, etc, cross-over to occur. In that problem you'll have to assume that only double cross-over occurred. Triple and quadruple are very unlikely and single would destroy the chromosome.

    So to start it up, you need to draw a map of all possible gene order (painful task) and look at all the possible location for cross-over and predict the possible recombinant and phenotype.

    For example

    Donor DNA___A______B______C_________D________E_____

    Possible recombination ABCDE, aBCDE, Abcde, etc

    Phenotype: doesn't need any compound, need compound a, need compound bcde, etc

    Since all your plate have three amino acid added, you only have to look at recombination that exclude 3 genes / fix two genes.
    Last edited: Jul 2, 2007
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