Figure 5.

Loss of SETDB1 leads to the induction of dsRNAs. (A) Confocal microscopy images of representative THP-1–Cas9 cells 5 d after nucleofection with synthetic gRNAs targeting CD81 (negative control, top) or SETDB1 (target sequence 6, bottom). Cells were stained with J2 antibody to label dsRNA and DAPI to mark nuclei. (B) qRT-PCR validated expression of bidirectionally transcribed LINEs and ERVs in THP-1–Cas9 cells after 5 d of treatment with SETDB1 sgRNAs or an NTC control sgRNA (n = 3 biological replicates). (C) RNase protection assay showing expression of dsRNAs in THP-1–Cas9 cells after 5 d of treatment with synthetic SETDB1-specific gRNAs after digestion of total RNA with RNase A/T1. ssRNA, single-stranded RNA. Enrichments are relative to NTC control sgRNA (n = 3 biological replicates, and Student’s t tests were performed). Error bars represent standard deviation.