F) oma-1(zu405) is a temperature sensitive (ts) lethal (embryonic arrest at temperatures > 20°C) allele of oma-1 (R. Lin 2003). oma-1 RNAi suppresses oma-1(zu405ts) lethality. Animals were exposed to oma-1 RNAi and the number of embryos that hatched was scored at 20°C. N=3. Error bars are +/- s.d. Animals harboring mutations in genes specifically required for the inheritance of RNAi would respond normally to direct exposure to oma-1 dsRNA but fail to inherit this silencing (Wan et al. 2018). zsp-1 mutants fail to respond immediately to direct exposure to oma-1 dsRNA, indicating that ZSP-1 is not specific to inheritance and, therefore, is generally required for RNAi (see also Fig. EV5B-D). 