what info is needed to map the chromosome of a bacterial species?

Question

Conjugation mapping can be used to locate genes on a bacterial chromosome. In this example, the F+ strain is able to synthesize methionine, valine, leucine, and histidine. The F- strain is unable to synthesize these amino acids; therefore, they must be supplied in the growth medium. Use the results from replica-plating to answer the questions.

Answer 1

you can map where the methionine, valine, leucine and histidine synthesis genes are on the F+ strain by transferring specific segments into the F- strain by conjugation.

1. Cojugate F+ and F- strains, allow DNA to transfer.

2. Grow the new F- strain up and plate on four replica plates, one lacking methionine, one lacking valine, one lacking leucine and one lacking histidine.

3. Determine which colonies are capable of growing on more than one amino acid lacking plate. The closer the two genes are in the F+ source, the more colonies that will grow on those two media plates.