FIG. 3.

Genetic mapping of the whiL mutant R214. R214 (inner circle) was crossed with strain 1258 (outer circle), and hisC⁺ and strA1 (indicated by solid triangles) were selected. Numbers in the diagram are the frequencies of alleles among the recombinant progeny. The segregation of the whi mutation with respect to proA1 is tabulated below. Of the three whiL mutants analyzed, R214 showed the largest number of Pro⁺ grey (multiple-crossover class) recombinants. The crosses with R349 and R491 gave 3 and 0 such recombinants, respectively.