Fig. 1.
Schematic of the round-robin experimental cross design. Each of the five wild-type populations is color coded: LHM (L, red), Innisfail (I, blue), Odder (O, green), Dahomey (D, orange), and Tasmania (T, purple). We crossed each wild-type population (large boxes) with two others from either a different continent or a different climate. This procedure generated four novel genotypes from each cross, so that every combination of the novel sex chromosome pairs experienced a different autosomal genetic background. In total, 10 Novel X and 10 Novel Y genotypes were generated (small boxes). We also generated two Novel XY genotypes from each population cross, where a sex chromosome pair were paired with a novel set of autosomes. Colored bars represent the two major chromosomes (II and III) and chromosome X, with chromosome Y depicted by a half arrow. Novel genotypes are annotated as “genetic background–origin of sex chromosome,” with the novel sex chromosome indicated by an X or Y subscript.