Fig. 1

A schematic diagram showing how traceable phenotypic selectable markers such as Rdl could be used in conjunction with tsl, especially if they are closely linked on the same chromosome. In a GSS chromosomal translocation involving tsl and Rdl, males are hemizygous for the wild-type alleles of both loci (marked as blue) which are translocated to the Y chromosome (shown predominantly in yellow), with a reciprocal translocation to the autosome. The remaining, intact autosome carries the mutant alleles of both tsl and Rdl loci (marked as red). Females, which lack the Y chromosome, are homozygous for the mutant alleles of both tsl and Rdl, conferring the mutant phenotypes that allow for male selection, i.e. treatment with either temperature or dieldrin kills females (♀ = female, ♂ = male).