Figure 2.—

Genetic mapping and segregation of novel tr-Ac. (A) Finely spotted kernels from F₁ ears (Figure 1) are testcrossed to the Ds tester (r1-sc:m3) to map the tr-Ac relative to the donor Ac element. The resulting ear will contain kernels that are doubly hemizygous for both Ac elements, hemizygous for one Ac element, or that do not contain any Ac insertions (r1 alleles not shown in schematic). (B) Crosses in which the tr-Ac is linked to the donor Ac will result in few coarsely spotted kernels (top ear). If the tr-Ac is unlinked to the donor Ac, approximately one-half of the kernels will be coarsely spotted (bottom ear).