Diagrams representing the organization of the ECM34 (in gray) and SSU1 (in black) nonrecombinant alleles and their corresponding recombinant variants obtained by an illegitimate crossing-over of a microhomology region (see Fig. 3), indicated by a vertical line, located in the promoters of both genes. This illegitimate crossing-over was involved in the generation of the reciprocal translocation between chromosomes VIII and XVI found inSaccharomyces strains (Fig. 1). Thick arrows represent the protein-coding regions of each gene. The pentagon block corresponds to a 76-bp sequence that has been found several times repeated in the promoters of both nonrecombinant ECM34 (strain CECT 1477) and recombinant SSU1-R (several strains). Strains bearing these sequences are indicated for each diagram.
