Figure 2 .

Tail phenotypes and genotypes in Tt-complex crosses. (A) Tail phenotypes and genotypes are indicated. (B) The balanced lethal cross. It appears that taillessness breeds true because the other two genotypes die as embryos. (C) Complementation between t-lethals. Now a class of normal-tailed compounds t^x/t^y appears. The numbers of each phenotype will not resemble Mendelian ratios because the male transmits the t-haplotype to 99% of the progeny. The female has normal transmission. Thus one can expect ∼50% normal tails and 50% tailless offspring. Male normal tails are sterile. A variation of C is when the cross involves two parents carrying a semilethal (t^sl). In this case, the phenotypes of the pups would be the same.