Homework SourseAn Hfr strain is used to map three genes in an interrupted m
An Hfr strain is used to map three genes in an interrupted mating experiment. The cross isHfr/a+b+c+rifs×F/abcrifr . (No map order is implied in the listing of the alleles; rifr is resistance to the antibiotic rifampicin.) The a+ gene is required for the biosynthesis of nutrient A, the b+ gene for nutrient B, and c+ for nutrient C. The minus alleles are auxotrophs for these nutrients. The cross is initiated at time = 0, and at various times, the mating mixture is plated on three types of medium. Each plate contains minimal medium (MM) plus rifampicin plus specific supplements that are indicated in the following table. (The results for each time interval are shown as the number of colonies growing on each plate.)
Extra info: Rifampicin eliminates the donor strain, which is rif^s
Based on these data, determine the approximate location on the chromosome of the a, b, and c genes relative to one another and to the F factor. Drag the appropriate labels to their respective targets. Note: not all targets will be used. PLEASE SPECIFY WHICH ONES TO LEAVE BLANK TOO :) thank you!!
Here are partially wrong/wrong attempts: PLEASE pay attention to these!
| Time of Interruption | ||||
| 5 min | 10 min | 15 min | 20 min | |
| Nutrients A and B | 0 | 0 | 4 | 21 |
| Nutrients B and C | 0 | 5 | 23 | 40 |
| Nutrients A and C | 4 | 25 | 60 | 82 |
Solution
Based on these data determine the approximate location on the chromosome of the a, b and c genes relative to one another and the F factor. Show your work.
answer
Grows on AB rif: has taken up C+
Grows on BC rif has taken up A+
Grows on AC rif has taken up B+
First is taken up B+,
next is taken up A+
final is taken up C+
Order is oriT, -------------B, A, C ---answer
