Figure 1.

Description of OIL genotypes and the cross to construct additional recombinants. (A) Diagram of original introgression lines (OILS). Solid black lines represent D. sechellia chromosome in D. simulans background. Dashed lines indicate the possible extent of the D. sechellia introgressions between visible markers. Four visible markers on chromosome 3 were used to categorize the OILs (scarlet, st; ebony, e; outspread, osp; pink, p). Introgression lines used for OA tolerance testing are denoted with green arrows (i.e., have a breakpoint between either st/e, e/osp, or both). (B) Diagram of fly cross to generate new introgression lines for OA tolerance assay. G₀ females are from OIL 8 and males are pure D. simulans. The recombinants of interest (G₁ males) were backcrossed to D. simulans females. The six recombinant genotypes (second line of cross) correspond to OILs numbered in green. Visible mutant phenotype was continually selected in males to preserve the haplotype without recombination. D. simulans background indicated by recessive mutations (st, e, osp, and p). Presence of D. sechellia introgression denoted by symbol for wild type (+). Recomb, the recombinant chromosome inherited from the G₀ female.