Journal Article

mut-16 and other mutator class genes modulate 22G and 26G siRNA pathways in Caenorhabditis elegans

Fischer, Sylvia E. J., Ruvkun, Gary, Phillips, Carolyn M., Carrington, James C., Gabel, Harrison W., Fahlgren, Noah, Zhang, Chi, Sullivan, Christopher M., Montgomery, Taiowa A.

2011

Overview

Argonaute-associated siRNAs and Piwi-associated piRNAs have overlapping roles in silencing mobile genetic elements in animals. In Caenorhabditis elegans, mutator (mut) class genes mediate siRNA-guided repression of transposons as well as exogenous RNAi, but their roles in endogenous RNA silencing pathways are not well-understood. To characterize the endogenous small RNAs dependent on mut class genes, small RNA populations from a null allele of mut-16 as well as a regulatory mut-16{mg461) allele that disables only somatic RNAi were subjected to deep sequencing. Additionally, each of the mut class genes was tested for a requirement in 26G siRNA pathways. The results indicate that mut-16 is an essential factor in multiple endogenous germline and somatic siRNA pathways involving several distinct Argonautes and RNAdependent RNA polymerases. The results also reveal essential roles for mut-2 and mut-7 in the ERGO-1 class 26G siRNA pathway and less critical roles for mut-8, mut-14, and mut-15. We show that transposons are hypersusceptible to mut-16-dependent silencing and identify a requirement for the siRNA machinery in piRNA biogenesis from Tel transposons. We also show that the somaspecific mut-16(mg461) mutant allele is present in multiple G elegans laboratory strains.

• Publisher: National Academy of Sciences,National Acad Sciences
• Subject: Alleles / Animals / biogenesis / Biological Sciences / Blotting, Northern / Caenorhabditis elegans / Caenorhabditis elegans - genetics / Caenorhabditis elegans Proteins - genetics / Datasets / DNA Transposable Elements - genetics / Embryo, Nonmammalian - metabolism / Exoribonucleases - genetics / Female / Gene expression / Gene Expression Profiling / Gene Expression Regulation, Developmental / Gene silencing / Genes / Genetic mutation / Genetic transposition / Germ cells / Germ Cells - metabolism / high-throughput nucleotide sequencing / Male / Messenger RNA / mutants / Mutation / Nematodes / null alleles / Population genetics / Reverse Transcriptase Polymerase Chain Reaction / Ribonucleic acid / RNA / RNA interference / RNA polymerase / RNA, Helminth - classification / RNA, Helminth - genetics / RNA, Helminth - metabolism / RNA, Small Interfering - classification / RNA, Small Interfering - genetics / RNA, Small Interfering - metabolism / RNA-Binding Proteins - genetics / RNA-directed RNA polymerase / RNA-mediated interference / Signal transduction / Signal Transduction - genetics / siRNA / Small interfering RNA / Species Specificity / Transposons