Question: Assume you have identified a mutant E. coli strain that cannot synthesize histidine (his-). To determine the location of the his- mutation on the E. coli chromosome,interrupted mating experiment was performed with 5 different Hfr strains. The results were as follows (transfer time in parenthesis):
Hfr A bio (4) glu 20 his 27 cys 37 tyr 45
Hfr B xyl 6 met 18 tyr 24 cys 32 his 42
Hfr C his 3 cys 13 tyr 21 met 27 xyl 39
Hfr D xyl 7 thr 25 lac 40 bio 48 glu 62
Hfr E his 4 glu 11 bio 27 lac 35 thr 50
On the map below of the circular E. coli chromosome, indicate:
a. relative location of each gene
b. position where the sex factor is integrated in each of the five Hfr strains
c. the direction of chromosome transfer for each Hfr (indicate with arrow)