Fig. 1.

Double-strand break model. Each red and blue line represents the same chromosomal region; the model shown is during meioses so there are two copies of both the red and blue chromosomes. The short black line represents a double-strand break on the red chromosome; some surrounding DNA has been lost and is then copied from the blue chromosome. The break can be resolved either through a conversion or a crossover event. The colored triangles and ovals represent potential locations for the hotspot motif: in this example, a motif at the triangle location loses one red copy and gains one blue one, whereas a motif at the oval location retains the original quantities.