Volume 3

Gene expression / Benjamin Lewin.

  • Lewin, Benjamin.
Date:
1974-1977
Catalogue details

Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: Gene expression / Benjamin Lewin. Source: Wellcome Collection.

    68/952 (page 48)
    relative frequency of recombination mutant in donor DNA ri recipient r22 recipient rl 0 0.89 r6 0.41 0.52 rl 0.17 0.78 r9 0.40 0.08 rll 0.14 0.69 r20 0.40 0.14 r22 0.50 0 r24 0.33 0.15 r25 0.07 0.74 r26 0.27 0.42 r27 0.03 0.79 order relative to rl recipient: r 1 r27 r25 r 11 = = = r7 0 0.03 0.07 0.14 0.17 r24- 0.33 order relative to r22 recipient: r22 r9 r20= = = r24 r26 r6 0 0.08 0.14 0.15 0.42 0.52 ri 1 r25 r27- 0.69 0.74 0.79 final genetic map: r22 r9 r20 r24 r6= = = r26 r7 rll r25 r27 rl The relative frequency of recombination is the number of wild type recombinants from the two point donor mutant x recipient mutant cross, as a proportion of the number of transformants obtained for a reference stf donor marker. The two recipient markers, rl and r22, lie at the two ends of this genetic segment; a map order of donor mutant sites relative to each recipient can be constructed from the recombination frequencies as shown. Mutant sites that are not resolved from each other in these crosses are connected by equality signs. By taking the cross with the rl recipient to define the sites of mutations close to rl, and by using the crosses with the r22 recipient to define the sites of mutations located close to r22, it is possible to produce a genetic map in which the only ambiguity is in the central region, concerning the positions of r6 and r26. Data of Sicard and Ephrussi-Taylor (1965). — r26 0.27 r20= = = r9= = =r6 r22 0.40 0.40 0.41 0.50 r7 rl 0.78 0.89