Fig. 2: Ribonucleotide incorporation during repair of chromosomal breaks.
(A, B) SP9 pre-B cells were induced for 24 hours, resulting in expression of RAG1+2 nuclease and introduction of chromosome breaks adjacent to VK and JK coding segments (boxes). % ribo. in VJK coding junctions was measured as in Fig. 1A. (B) Data points are the mean of five independent inductions, and error bars represent sd. Means were compared in pairs as noted by ANOVA (***; p < 0.001). (C, D) Rosa26 locus-targeting Cas9 ribonucleoprotein was introduced into MEFs deficient in Rnaseh2a and expressing TdT. % ribo. was detected as in Fig. 1A using a qPCR specific for the TdT-dependent +GG product (also Fig. S4). (D) Data points are the mean of 3 independent transfections, and error bars represent sd.