Figure 4.

Ty1 integration pattern upstream of a single and multiple copies of tGly^GCC in the bdp1-Δ240 and isw2-K215R single mutants and the bdp1-Δ240isw2-K215R double mutant. (Top) The orientation 1 primer was combined with the tGly^GCC primer to amplify insertions upstream of the family of tGly^GCC genes. (Bottom) Insertions upstream of a single tGly^GCC, tG(GCC)G2, were amplified using the orientation 1 primer and a primer complementary to unique sequence downstream of the tRNA gene. The resulting products are therefore larger than those generated in the top panel. Two independent transformants of each strain are shown. Circles denote the four bands characteristic of periodic Ty1 integration, and triangles denote the major bands present in the mutant strains but not in the wild type.