Variation of the recombination fraction in Drosophila melanogaster females.

The distribution of the recombination fraction between two distal, autosomal loci, plexus and orange, was investigated in reciprocal crosses between the marker stock and each of two wild-type strains, Harwich and Ottawa. The dysgenic cross between Harwich males and marker females exhibited high sterility, low fecundity, and a non-normal distribution of the recombination fraction. Neither the distribution of the reciprocal Harwich cross nor those of the two Ottawa crosses deviated from normal. In general, the results support the view that the recombination fraction is a variable.