E.coli with minimal media problem, HELP

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Discussion Overview

The discussion revolves around a homework problem related to E. coli genetics, specifically focusing on determining gene order from experimental data involving minimal media and the inability of certain E. coli strains to synthesize specific compounds. The scope includes genetic mapping and recombination analysis.

Discussion Character

  • Homework-related
  • Technical explanation

Main Points Raised

  • One participant expresses uncertainty about how to begin solving the problem, noting the E. coli strain's inability to produce five compounds and the significance of the colonies in indicating missing genes.
  • Another participant requests clarification on the data by asking for a link to the picture that was mentioned but not initially provided.
  • After the file is shared, a participant explains that the problem involves classical genetics techniques, emphasizing the role of recombination and the assumption that only double cross-overs occurred, while also noting the rarity of triple and quadruple cross-overs.
  • The same participant suggests creating a map of possible gene orders and predicting recombinant phenotypes based on cross-over locations, providing an example of how to visualize the gene arrangement and potential outcomes.

Areas of Agreement / Disagreement

Participants do not appear to reach a consensus, as there is a mix of uncertainty about the initial approach and differing levels of understanding regarding the genetic mapping process.

Contextual Notes

The discussion includes assumptions about the types of cross-overs that can occur and the implications for gene mapping, but these assumptions are not universally accepted or confirmed within the thread.

Intr3pid
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Homework Statement


in the picture/attached file



Homework Equations


no equations necessary


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?

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

The attached file is not present.
 
sorry about that, here's the file.
 

Attachments

  • mininal media question.GIF
    mininal media question.GIF
    62.4 KB · Views: 584
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_____
Cross-over_1______2_____3_______4_________5_______6
Recipent____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:

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