You perform a generalized transduction experiment where phag

You perform a generalized transduction experiment, where phages are collected from an S. aureus donor strain of genotype abc+ def+ ghi+, then used to transduce a recipient of genotype abc- def- ghi-. The recipients were plated on minimal medium supplemented with def and ghi. You see lots of colonies. List the genotypes found in the colonies Colonies are replicated onto three different media, (1) minimal plus ghi only, (2) minimal plus def only, (3) minimal. In theory, what genotypes would grow? Growth was observed at 58% on medium 1, 7% growth was observed on medium 2, and no colonies observed on medium 3. What are the genotypes of the colonies on each medium?

Solution

a) The genotypes found in the colonies will be abc+ def+ ghi+; abc+ def- ghi-, abc+ def- ghi+ and abc+ def+ ghi-.

b) 1- Minimal plus ghi only - This plate will have abc+ def+ ghi+ and abc+ def+ ghi-

2 - Minimal plus def only - This plate will have abc+ def+ ghi+ and abc+ def- ghi+

3- Minimal - abc+ def+ ghi+ only

c) Since the medium 3 did not have any colony the genotype in each medium will be

1- Minimal plus ghi only - abc+ def+ ghi-

2 - Minimal plus def only - abc+ def- ghi+,

3- Minimal - No colonies.