Fig. S4.

Synthesis at ends that align to generate three nucleotide gaps. Repair junctions recovered from WT and Poll^−/− cells are categorized as consistent with formation by polymerase and ligase activity alone (e.g., as in Figs. 1–4), formation after nuclease activity limited to overhang sequence (overhang remodeled), or formation after nuclease activity removes all overhang sequence (dsDNA deletion and overhangs removed). The number of sequences for each junction type and representation as a percentage of the total analyzed is shown. Accurate fill-in synthesis was significantly reduced in Poll^−/− relative to WT cells (*confidence level, P < 0.05 by Fisher’s exact test).