Using donor DNA from an E. coli strain of leu+ arg+ trp- you transform a resipient strain that is leu- arg- trp+ and select for leu+. The resulting 100 colonies are then screened for the arg and trp markers and the results are outlined in the table below.

Question

genotype # of colonies
1. arg+ trp+ 8
2. arg- trp- 47
3. arg+ trp- 18
4. arg- trp+ 27

Determine the order of the genes and relative map distances.