Fig. 1.

Experimental (A) and control (B) breeding protocols. X₁, X₂,..., X₅ represent hypothetical distinct alleles at the sex locus. The experimental and control pedigrees differ in that biparental diploid F₂ males (male a) were used in the experimental lineage and uniparental haploid males (male b) were used in the control lineage. According to the current understanding of sl-CSD, if diploid males are fertile, their offspring (F₃ female c) should be triploid and sterile and no F₄ offspring should be produced.