Genetic evidence that ESC4 and SLX4 function together in a parallel pathway to SGS1 for repair of damaged DNA. Strains were grown in YPD medium to saturation and then ten-fold serial dilutions were spotted onto YPD, YPD + HU (100 mM), or YPD + MMS (0.032% in part A and 0.014% in part B) media. Cells were incubated at 30°C for 2 days (SC and SC + MMS) or 3 days (SC + HU) before being photographed. WT, wild type. An asf1 Δ mutant was used as a positive control for MMS and HU sensitivity.