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Received August 31, 2012; Revision received October 31, 2012
Recently, using large-scale genomic sequencing, a great number of small noncoding RNAs (ncRNA) has been discovered. Short ncRNAs can be classified into three major classes – small interfering RNA (siRNA), microRNA (miRNA), and piwi-interacting RNA (piRNA). These short ncRNAs ranging from 20 to 300 nt in size are now recognized as a new paradigm of gene regulation for controlling many biological processes. In this paper, we review the biogenesis and recent research on the functions of small regulatory non-coding RNAs and aim at understanding their important functions in living organisms.
KEY WORDS: miRNAs, siRNAs, piRNAs, biogenesis, regulation, functions