An interrupted mating study is carried out on Hfr strains 1, 2, and 3 identified in Problem 17. After conjugation is established, a small sample of the mixture is collected every minute for 20 minutes to determine the distance between genes on the chromosome. Results for each of the three Hfr strains are shown below. The total duration of conjugation (in minutes) is given for each transferred gene.Hfr strain 1 oriT met ala lac galDuration (min) 0 2 8 13 17Hfr strain 2 oriT met leu thr aziDuration (min) 0 2 7 10 17Hfr strain 3 oriT gal pro trp aziDuration (min) 0 3 8 14 19Using the chromosome map you prepared in answer to Problem 17, determine the distance in minutes between each gene on the map.

Hfr strains that differ in integrated F factor orientation and site of integration are used to construct consolidated bacterial chromosome maps. The data below show the order of gene transfer for five strains.

Hfr Strain       Order of Gene Transfer (First → Last)
Hfr A                oriT–thr–leu–azi–ton–pro–lac–ade
Hfr B                oriT–mtl–xyl–mal–str–his
Hfr C                oriT–ile–met–thi–thr–leu–azi–ton
Hfr D                oriT–his–trp–gal–ade–lac–pro–ton
Hfr E                oriT–thi–met–ile–mtl–xyl–mal–str

Draw a consolidated map of the bacterial chromosome. (Hint: Begin by placing the insertion site for Hfr A at the 2 o'clock position and arranging the genes thr–leu–azi- . . . in clockwise order.)

Hfr strains that differ in integrated F factor orientation and site of integration are used to construct consolidated bacterial chromosome maps. The data below show the order of gene transfer for five strains.

Hfr Strain       Order of Gene Transfer (First → Last)
Hfr A                oriT–thr–leu–azi–ton–pro–lac–ade
Hfr B                oriT–mtl–xyl–mal–str–his
Hfr C                oriT–ile–met–thi–thr–leu–azi–ton
Hfr D                oriT–his–trp–gal–ade–lac–pro–ton
Hfr E                oriT–thi–met–ile–mtl–xyl–mal–str

Identify the overlaps between Hfr strains. Identify the orientations of integrated F factors relative to one another.

Five Hfr strains from the same bacterial species are analyzed for their ability to transfer genes to F⁻ recipient bacteria. The data shown below list the origin of transfer (oriT) for each strain and give the order of genes, with the first gene on the left and the last gene on the right. Use the data to construct a circular map of the bacterium.

Hfr Strain          Genes Transferred
Hfr 1                  oriT met ala lac gal
Hfr 2                  oriT met leu thr azi
Hfr 3                  oriT gal pro trp azi
Hfr 4                  oriT leu met ala lac
Hfr 5                  oriT trp azi thr leu met

An interrupted mating study is carried out on Hfr strains 1, 2, and 3 identified in Problem 17. After conjugation is established, a small sample of the mixture is collected every minute for 20 minutes to determine the distance between genes on the chromosome. Results for each of the three Hfr strains are shown below. The total duration of conjugation (in minutes) is given for each transferred gene.

Hfr strain 1           oriT     met     ala     lac     gal
Duration (min)       0          2        8       13      17
Hfr strain 2           oriT     met     leu     thr      azi
Duration (min)       0          2        7       10      17
Hfr strain 3           oriT     gal      pro     trp      azi
Duration (min)       0          3        8       14      19

In minutes, what is the total length of the chromosome in the donor species?

An interrupted mating study is carried out on Hfr strains 1, 2, and 3 identified in Problem 17. After conjugation is established, a small sample of the mixture is collected every minute for 20 minutes to determine the distance between genes on the chromosome. Results for each of the three Hfr strains are shown below. The total duration of conjugation (in minutes) is given for each transferred gene.

Hfr strain 1           oriT     met     ala     lac     gal
Duration (min)       0          2        8       13      17
Hfr strain 2           oriT     met     leu     thr      azi
Duration (min)       0          2        7       10      17
Hfr strain 3           oriT     gal      pro     trp      azi
Duration (min)       0          3        8       14      19

Write out the interrupted mating results you would expect after 20 minutes of conjugation for Hfr strains 4 and 5. Use the format shown at the beginning of this problem.

An interrupted mating study is carried out on Hfr strains 1, 2, and 3 identified in Problem 17. After conjugation is established, a small sample of the mixture is collected every minute for 20 minutes to determine the distance between genes on the chromosome. Results for each of the three Hfr strains are shown below. The total duration of conjugation (in minutes) is given for each transferred gene.

Hfr strain 1           oriT     met     ala     lac     gal
Duration (min)       0          2        8       13      17
Hfr strain 2           oriT     met     leu     thr      azi
Duration (min)       0          2        7       10      17
Hfr strain 3           oriT     gal      pro     trp      azi
Duration (min)       0          3        8       14      19

Explain why azi is the last gene of strain 2 to transfer in the 20 minutes of conjugation time. How many minutes of conjugation time would be needed to allow the next gene on the map to transfer from Hfr strain 2?