biostudies-literatureUebel CJNIGMS NIH HHS3719-3728https://www.ebi.ac.uk/biostudies/studies/S-EPMC7534428biostudies-literatureUnknown10(10)RNA interference is a crucial gene regulatory mechanism in <i>Caenorhabditis elegans</i> Phase-separated perinuclear germline compartments called <i>Mutator</i> foci are a key element of RNAi, ensuring robust gene silencing and transgenerational epigenetic inheritance. Despite their importance, <i>Mutator</i> foci regulation is not well understood, and observations of <i>Mutator</i> foci have been largely limited to adult hermaphrodite germlines. Here we reveal that punctate <i>Mutator</i> foci arise in the progenitor germ cells of early embryos and persist throughout all larval stages. They are additionally present throughout the male germline and in the cytoplasm of post-meiotic spermatids, suggestive of a role in paternal epigenetic inheritance. In the adult germline, transcriptional inG3 (Bethesda, Md.)<i>Mutator</i> Foci Are Regulated by Developmental Stage, RNA, and the Germline Cell Cycle in <i>Caenorhabditis elegans</i>.PMC7534428T32 GM118289R35 GM119656Phillips CMWallis DCAgbede DUebel CJfalse<i>Mutator</i> Foci Are Regulated by Developmental Stage, RNA, and the Germline Cell Cycle in <i>Caenorhabditis elegans</i>.RNA interference is a crucial gene regulatory mechanism in <i>Caenorhabditis elegans</i> Phase-separated perinuclear germline compartments called <i>Mutator</i> foci are a key element of RNAi, ensuring robust gene silencing and transgenerational epigenetic inheritance. Despite their importance, <i>Mutator</i> foci regulation is not well understood, and observations of <i>Mutator</i> foci have been largely limited to adult hermaphrodite germlines. Here we reveal that punctate <i>Mutator</i> foci arise in the progenitor germ cells of early embryos and persist throughout all larval stages. They are additionally present throughout the male germline and in the cytoplasm of post-meiotic spermatids, suggestive of a role in paternal epigenetic inheritance. In the adult germline, transcriptional in2020-01-01T00:00:00Z2020 Oct2025-05-29T20:51:37.259Z2020-10-29T09:32:12ZS-EPMC75344283276395210.1534/g3.120.401514