FIG. 3.

Homologous-sequence length dependence of SSA. Strains containing the two-repeat substrate (Fig. 2A) were constructed with various amounts of homologous DNA. The sizes tested were 29, 63, 89, 205, 235, 415, and 1,170 bp. The frequency of SSA was determined, as described in detail in Materials and Methods, by quantitating the product band and dividing by the quantity of uncut uninduced band and normalizing to an independent band (after reprobing with leu2) and to the number of cells containing the GAL::HO plasmid. Strain tNS709, with 29-bp repeats, was analyzed separately to exclude NHEJ and religation events as well as uninduced cells (wild type [WT]) as described in the text.