Fig. 2. Validation of candidate synthetic lethal pairs.

A Schematic of the competitive growth assay. Cas9-expressing cells were infected with lentiviruses expressing each gRNA in a BFP or mCherry vector to create four populations and read by FACS at day 4 and 14. B Example of a synthetic lethal pair. A375-Cas9 cells were transduced with lentiviruses expressing CNOT7 (BFP) and CNOT8 (mCherry) sgRNAs and analysed at two timepoints. The growth phenotype was calculated by measuring the relative depletion of the single-infected and double-infected cells. C Residual values from competitive growth experiments. Residuals were calculated as the difference between the expected phenotype of the double-positive population (based on summing the phenotypes of the single positive populations) and the observed phenotype of the double-positive population. Data represent three independent transductions. The baseline residual for three non-interacting-pairs (negative controls) are also shown (AIPL1&ACCSL, AIPL1&ASF1B, TTC7A/ACCSL). Residuals were compared with values for the control ACCSL/AIPL1 gene pair. Significance was calculated using a one-way ANOVA and adjusted for multiple testing using the Dunnett test. All interactions, except where indicated, had a P value < 0.01.