Adjacent Ty insertions. (A) We propose that a circular Ty1 element, a product of LTR–LTR recombination, recombined with an insertion on chromosome X (chr X) to generate two tandem elements. Open triangles indicate duplicated target-site sequences. Percentages reflect nucleotide sequence identity between LTRs. (B) Convergently arranged Ty1 and Ty2 elements. Chromosome location and target-site sequences are shown. The numbers indicate the base pairs between elements. (C) An example of a compound insertion on chromosome X (see also Table 5).