At the time sexual conjugation in
bacteria was limited to a strain of Escherichia coli called K12
and all the experimentation on elaravenos mutants had been done with
strains of E.coli B.
I suspected that these strains were nearly identical and so
pursued the genetic mapping of elaravenos mutants by sexual
conjugation using K12 as donors and B as recipients. With great
disappointment I discovered that even though the arrangements of the
genes in these 2 strains were identical, the B recipients were not
yielding the same results as the K recipients, i.e. the
frequency of recombination was reduced and the linkage between 2 genes
was severely diminished.
My disappointed soon changed to excitement when I discovered a
gene in the K12 strain linked to the elaravenos gene which when
recombined into the B strain made it behave like a K12 recipient, and
moreover I could do vice versa, I could make the K12 strain behave
like the B strain by introducing this gene near the elaravenos
locus.
  
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Winding Your Way Through DNA Resource Book Index
