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RNA Interference in Animals

Epigenetic Regulation and Epigenomics

  1. Mikiko C. Siomi

Published Online: 15 MAY 2012

DOI: 10.1002/3527600906.mcb.201100037

Reviews in Cell Biology and Molecular Medicine

Reviews in Cell Biology and Molecular Medicine

How to Cite

Siomi, M. C. 2012. RNA Interference in Animals. Reviews in Cell Biology and Molecular Medicine. .

Author Information

  1. Keio University School of Medicine, Department of Molecular Biology, Tokyo, Japan

Publication History

  1. Published Online: 15 MAY 2012

This is not the most recent version of the article. View current version (30 APR 2014)


Each of the cells of which a living body is composed (with a few exceptions, such as spermatozoa, eggs, and anucleated and multinucleated cells) contains an identical set of genes. Yet, their expression is not identical; rather, it is regulated by multiple, complex mechanisms in a spatiotemporal and cell-specific manner. RNA interference (RNAi) is one of several gene-expression regulatory mechanisms that are necessary to generate cellular complexity and to orchestrate cellular events. RNAi is triggered by small RNAs, ranging from 20 to 30 nt in length, which show a high level of complementarity to their target genes. However, small RNA is unable to induce RNAi alone, and to accomplish the task it must form the core of the RNA–protein complex termed the RNA-induced silencing complex (RISC), specifically with Argonaute protein. Argonaute is the main effector protein in RNAi, whereby Argonaute is guided to its targets by bound small RNA. The fact that both Argonaute and small RNAs are highly conserved across species implies that RNAi is a fundamental, biological process that is required by living creatures. During recent years, the anticipation of RNAi as a new form of disease therapy has been steadily growing, based mainly on its high specificity and efficacy with regards to recognizing target genes and disrupting their expression.


  • Argonaute;
  • Dicer;
  • RISC