Figure 4.—

(A) Test for an X–autosome interaction. D. sechellia females heterozygous for hlx^mau were crossed to D. mauritiana males. If hlx^mau-bearing hybrid males are viable, D. mauritiana possesses one or more dominant, autosomal suppressors of hlx^mau. (B) A genetic mapping screen for Su(hlx) in D. mauritiana autosomal genome. D. simulans females heterozygous for hlx^mau are crossed to D. sechellia males homozygous for small autosomal introgressions from D. mauritiana. If hlx^mau-bearing males are viable, the D. mauritiana introgression possesses a dominant Su(hlx).