The role of the Cer1 transposon in horizontal transfer of transgenerational memory. Author Rebecca Moore, Rachel Kaletsky, Chen Lesnik, Vanessa Cota, Edith Blackman, Lance Parsons, Zemer Gitai, Coleen Murphy Publication Year 2021 Type Journal Article Abstract Animals face both external and internal dangers: pathogens threaten from the environment, and unstable genomic elements threaten from within. C. elegans protects itself from pathogens by "reading" bacterial small RNAs, using this information to both induce avoidance and transmit memories for four generations. Here, we found that memories can be transferred from either lysed animals or from conditioned media to naive animals via Cer1 retrotransposon-encoded virus-like particles. Moreover, Cer1 functions internally at the step of transmission of information from the germline to neurons and is required for learned avoidance. The presence of the Cer1 retrotransposon in wild C. elegans strains correlates with the ability to learn and inherit small-RNA-induced pathogen avoidance. Together, these results suggest that C. elegans has co-opted a potentially dangerous retrotransposon to instead protect itself and its progeny from a common pathogen through its inter-tissue signaling ability, hijacking this genomic element for its own adaptive immunity benefit. Keywords Animals, Caenorhabditis elegans, Gene Expression Regulation, RNA, Behavior, Animal, Memory, RNA Interference, Virion, Germ Cells, Genome, Extracellular Vesicles, Avoidance Learning, DNA Transposable Elements, Inheritance Patterns, Gene Transfer, Horizontal Journal Cell Volume 184 Issue 18 Pages 4697-4712.e18 Date Published 2021 Sep 02 ISSN Number 1097-4172 DOI 10.1016/j.cell.2021.07.022 Alternate Journal Cell PMCID PMC8812995 PMID 34363756 PubMedPubMed CentralGoogle ScholarBibTeXEndNote X3 XML