Fig. 2. Effect of DNA divergence and distance between inverted Alu repeats on their ability to stimulate recombination. (A) Effect of sequence divergence. Squares, recombination rates with IRs separated by 12 bp (see Table I). For 99.7% homologous inverted Alu repeats only data for IRs where a single mismatch was located at the 5′ end (i.e. close to the 12 bp spacer) are presented (see Results). Dotted line, level of recombination (4 × 10^–7) in a strain containing a direct Alu repeat. (B) Effect of the distance between inverted Alus. Squares and triangles, recombination rates with 100 and 94% identical IRs, respectively. Dotted line, level of recombination (4 × 10^–7) in a strain containing a direct Alu repeat.