18S rRNA methyltransferases DIMT1 and BUD23 drive intergenerational hormesis

Heritable non-genetic information can regulate a variety of complex phenotypes. However, what specific non-genetic cues are transmitted from parents to their descendants are poorly understood. Here, we perform metabolic methyl-labeling experiments to track the heritable transmission of methylation from ancestors to their descendants in the nematode Caenorhabditis elegans (C. elegans). We find heritable methylation in DNA, RNA, proteins, and lipids. We find that parental starvation elicits reduced fertility, increased heat stress resistance, and extended longevity in fed, naïve progeny. This intergenerational hormesis is accompanied by a heritable increase in N6ʹ-dimethyl adenosine (m6,2A) on the 18S ribosomal RNA at adenosines 1735 and 1736. We identified DIMT-1/DIMT1 as the m6,2A and BUD-23/BUD23 as the m7G methyltransferases in C. elegans that are both required for intergenerational hormesis, while other rRNA methyltransferases are dispensable. This study labels and tracks heritable non-genetic material across generations and demonstrates the importance of rRNA methylation for regulating epigenetic inheritance. [Display omitted] •Performed metabolic methyl-labeling to track heritable material across generations•Identified heritable N6-dimethylation of adenosines 1735 and 1736 on ribosomal RNA•Identified and characterized DIMT-1 and BUD-23 as m6,2A and m7G methyltransferases•Found dimt-1 and bud-23 necessary for transmission of heritable starvation response Liberman et al. labeled and tracked heritable non-genetic information from parents to their children. They identified that m6,2A methylated rRNAs are transmitted across generations in response to parental starvation. This paper identified that ribosome heterogeneity helps subsequent generations prepare for harsh conditions.