Figure 2.—

Relative effects of each QTL on hybrid male sterility. Hybrid male genotypes are given on the y-axis and sterility (as determined by sperm motility) is given on the x-axis. Heterozygous QTL (hybrid males carry both the D. persimilis and D. p. bogotana alleles) are indicated by shaded rectangles, and homozygous QTL (hybrid males carry only the D. p. bogotana allele) are indicated by open rectangles. A marker associated with each QTL is used to determine the average sterility of males hetero- or homozygous for that QTL. “N” is the number of males of a given genotype.