henn-1/HEN1 Promotes Germline Immortality in Caenorhabditis elegans
Joshua M. Svendsen,
Kailee J. Reed,
Tarah Vijayasarathy,
Brooke E. Montgomery,
Rachel M. Tucci,
Kristen C. Brown,
Taylor N. Marks,
Dieu An H. Nguyen,
Carolyn M. Phillips,
Taiowa A. Montgomery
Affiliations
Joshua M. Svendsen
Department of Biology, Colorado State University, Fort Collins, CO 80523, USA; Cell and Molecular Biology Program, Colorado State University, Fort Collins, CO 80523, USA
Kailee J. Reed
Department of Biology, Colorado State University, Fort Collins, CO 80523, USA; Cell and Molecular Biology Program, Colorado State University, Fort Collins, CO 80523, USA
Tarah Vijayasarathy
Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
Brooke E. Montgomery
Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
Rachel M. Tucci
Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
Kristen C. Brown
Department of Biology, Colorado State University, Fort Collins, CO 80523, USA; Cell and Molecular Biology Program, Colorado State University, Fort Collins, CO 80523, USA
Taylor N. Marks
Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
Dieu An H. Nguyen
Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
Carolyn M. Phillips
Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
Taiowa A. Montgomery
Department of Biology, Colorado State University, Fort Collins, CO 80523, USA; Corresponding author
Summary: The germline contains an immortal cell lineage that ensures the faithful transmission of genetic and, in some instances, epigenetic information from one generation to the next. Here, we show that in Caenorhabditis elegans, the small RNA 3′-2′-O-methyltransferase henn-1/HEN1 is required for sustained fertility across generations. In the absence of henn-1, animals become progressively less fertile, becoming sterile after ∼30 generations at 25°C. Sterility in henn-1 mutants is accompanied by severe defects in germline proliferation and maintenance. The requirement for henn-1 in transgenerational fertility is likely due to its role in methylating and, thereby, stabilizing Piwi-interacting RNAs (piRNAs). However, despite being essential for piRNA stability in embryos, henn-1 is not required for piRNA stability in adults. Thus, we propose that methylation is important for the role of piRNAs in establishing proper gene silencing during early stages of development but is dispensable for their role in the proliferated germline. : Svendsen et al. identify a requirement for the small RNA methyltransferase HENN-1 in germline immortality. HENN-1 is required for piRNA stability during embryogenesis but is dispensable in the adult germline, pointing to a role for piRNAs in establishing a gene regulatory network in embryos that protects the germline throughout development. Keywords: miRNA, piRNA, siRNA, Argonaute, C. elegans, hen1, piwi, methylation, transgenerational, RNAi
