asd-9 and rsd-6, but not asd-2, are required for biogenesis or stability of primary viral siRNAs. (A) Accumulation of FR1gfp genomic and subgenomic RNAs in asd-2 (1029e), asd-9 (1026d), and rsd-6 (1026a) after heat induction. The replication of FR1gfp in wild-type N2 worms and drh-1, rde-1, and rde-4 mutants was also detected as references. (B) Northern blot detection of FR1gfp-derived primary siRNAs in asd-2 (1029e), asd-9 (1026d), rsd-6 (1026a), and control worm strains. The accumulation of miR-58 was also detected as an equal loading control.