Fig. 2.

Synthesis primed from ends with a paired 3′ terminus. The recovery efficiencies for junctions formed after synthesis were determined as in Fig. 1B for cells transfected with (A) G3′-blunt or (B) GCG3′ substrates. Error bars and statistics were determined as in Fig. 1B. (C) The percentage of junctions associated with accurate synthesis was determined after introduction of the GCG3′ substrate together with 0, 0.1, 1, 10, or 100 ng of Pol λ into Polm^−/−Poll^−/− cells, and mean frequencies and error bars derived as in Fig. 1. (D) Cartoon describing the primer contexts preferred by Pol μ and Pol λ for synthesis activity associated with cellular NHEJ.