The Transposable Element Ds Affects the Pattern of Intragenic Recombination at the bz and R Loci in Maize

Insertion of the transposable element Ds into either the bz or R locus affects intragenic recombination in various ways. We have examined here one aspect of this problem; namely, the distribution of flanking markers among intragenic recombinations produced by different types of heterozygotes carrying Ds insertion mutations. Heteroallelic combinations of a Ds insertion mutation and a mutation borne on a structurally normal chromosome generate a majority of intragenic recombinants of a crossover type. In contrast to this, most intragenic recombinants obtained from heterozygotes between two different Ds insertion mutations have a parental arrangement of outside markers. Therefore, the resolution of the recombination intermediate would appear to depend on the nature of the mutations in the heterozygote.