Figure 5. Complementation Testcrosses.

For each testcross, heterozygous animals from independent lethal pedigrees (see Table 1) were intercrossed to obtain offspring that inherited both copies of their respective mutagenized chromosomes as detected by PCR genotyping or balancer screening (see Figure 1B). Noncomplementation (−) and complementation (+) divided the lethal pedigrees into at least six complementation groups, with two major groups labeled I and II. Pedigrees highlighted in pink complemented every other pedigree tested except one case, where AX failed to complement AS. Pedigrees in blue failed to complement pedigrees other than AG, AX, and BC (purple).