RNA interference (RNAi) was originally described as a gene silencing mechanism triggered by the experimental introduction of double stranded (ds)RNA into the nematode C. elegans (Fire et al., 1998). The term RNAi is now used to refer to a diverse set of gene regulatory mechanisms that share common features including the involvement of a short 21-30 nucleotide (nt) long RNA and a protein cofactor of the Argonaute (RNase H-related) protein family. As an experimental tool, RNAi is of broad relevance to basic medical research in numerous fields, and RNAi therapeutics are now under development for several clinical applications. Furthermore, RNAi-related mechanisms function in conserved gene-regulatory pathways that are of basic and fundamental importance to human cellular and developmental biology. The proposed genetic and biochemical studies will advance our understanding of RNAi and related pathways. The ability to combine classical genetics with the newer disciplines of deep-sequencing, functional genomics and proteomics, make C. elegans an ideal system for these studies. In all animals studied to date, multiple RNAi-related pathways co-exist within cells. In C. elegans, three AGO pathways have the potential to mediate genome-wide or transcriptome-wide surveillance. These pathways are: (i) the WAGO pathway, which targets transposons, pseudogenes and other cryptic loci, as well as some protein encoding genes;(ii) the CSR-1 pathway, which targets most, if not all, protein-encoding mRNAs expressed in the germ line;and (iii) the PRG-1 pathway, which targets at least one transposon family but has more than fifteen thousand additional genomically-encoded small RNA cofactors whose targets are not known. An important goal of this work is to understand how these distinct pathways identify targets and mediate specific regulatory outcomes. The proposed studies will investigate the function and interrelationship of these pathways, using an array of biochemical, molecular and genetic approaches. The mechanisms and protein families that mediate RNAi are highly conserved in animals, therefore, insights from the proposed studies will be directly relevant to human biology and disease. PHS 398/2590 (Rev. 09/04, Reissued 4/2006) Page Continuation Format Page

Public Health Relevance

Project Narrative RNA interference (RNAi) is a highly conserved gene-silencing mechanism implicated in immunity, genome maintenance and developmental gene regulation in both plants and animals. The goal of this project is to investigate RNAi and related mechanisms so that we can better understand how they impact on development and human health. Insights from these studies may lead directly to new RNA-interference technologies for probing gene function in a variety of organisms including humans, and may ultimately lead to new diagnostics and therapeutics.

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
Research Project (R01)
Project #
Application #
Study Section
Molecular Genetics B Study Section (MGB)
Program Officer
Bender, Michael T
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of Massachusetts Medical School Worcester
Other Basic Sciences
Schools of Medicine
United States
Zip Code
Shirayama, Masaki; Stanney 3rd, William; Gu, Weifeng et al. (2014) The Vasa Homolog RDE-12 engages target mRNA and multiple argonaute proteins to promote RNAi in C. elegans. Curr Biol 24:845-51
Poole, Catherine B; Gu, Weifeng; Kumar, Sanjay et al. (2014) Diversity and expression of microRNAs in the filarial parasite, Brugia malayi. PLoS One 9:e96498
Kim, Heesun; Ishidate, Takao; Ghanta, Krishna S et al. (2014) A co-CRISPR strategy for efficient genome editing in Caenorhabditis elegans. Genetics 197:1069-80
Conine, Colin C; Moresco, James J; Gu, Weifeng et al. (2013) Argonautes promote male fertility and provide a paternal memory of germline gene expression in C. elegans. Cell 155:1532-44
Gu, Weifeng; Claycomb, Julie M; Batista, Pedro J et al. (2011) Cloning Argonaute-associated small RNAs from Caenorhabditis elegans. Methods Mol Biol 725:251-80
Vasale, Jessica J; Gu, Weifeng; Thivierge, Caroline et al. (2010) Sequential rounds of RNA-dependent RNA transcription drive endogenous small-RNA biogenesis in the ERGO-1/Argonaute pathway. Proc Natl Acad Sci U S A 107:3582-7
Conine, Colin C; Batista, Pedro J; Gu, Weifeng et al. (2010) Argonautes ALG-3 and ALG-4 are required for spermatogenesis-specific 26G-RNAs and thermotolerant sperm in Caenorhabditis elegans. Proc Natl Acad Sci U S A 107:3588-93
Claycomb, Julie M; Batista, Pedro J; Pang, Ka Ming et al. (2009) The Argonaute CSR-1 and its 22G-RNA cofactors are required for holocentric chromosome segregation. Cell 139:123-34
Gu, Weifeng; Shirayama, Masaki; Conte Jr, Darryl et al. (2009) Distinct argonaute-mediated 22G-RNA pathways direct genome surveillance in the C. elegans germline. Mol Cell 36:231-44
Batista, Pedro J; Ruby, J Graham; Claycomb, Julie M et al. (2008) PRG-1 and 21U-RNAs interact to form the piRNA complex required for fertility in C. elegans. Mol Cell 31:67-78

Showing the most recent 10 out of 20 publications