Reported transgenerational responses toPseudomonas aeruginosainC. elegansare not robust

Here we report our attempt to replicate reports of transgenerational epigenetic inheritance inCaenorhabditis elegans. Published results from multiple laboratories show thatC. elegansadults and their F1 embryos exposed to the pathogenPseudomonas aeruginosashow pathogen aversion behavior and a pathogen exposure-dependent increase indaf-7/TGFβreporter gene expression. However, results from one group show persistence of the aversion behavior and elevateddaf-7expression in the F2, F3, and F4 generations. In contrast, we failed to consistently detect either the pathogen avoidance response or elevateddaf-7expression beyond the F1 generation. We did confirm that the dsRNA transport proteins SID-1 and SID-2 are required for the intergenerational (F1) inheritance of pathogen avoidance, but not for the F1 inheritance of elevateddaf-7expression. Furthermore, our reanalysis of RNA seq data provides additional evidence that this intergenerational inherited PA14 response may be mediated by small RNAs. The experimental methods are well-described, the source materials are readily available, including samples from the reporting laboratory, and we explored a variety of environmental conditions likely to account for lab-to-lab variability. None of these adjustments altered our results. We conclude that this example of transgenerational inheritance lacks robustness, confirm that the intergenerational avoidance response, but not the elevateddaf-7p::gfpexpression in F1 progeny, requiressid-1andsid-2, and identify candidate siRNAs and target genes that may mediate this intergenerational response.