Mouse Piwi-interacting RNAs are 2′-O-methylated at their 3′ termini

Abstract
Piwi-interacting RNAs (piRNAs) are a novel class of small RNAs that are expressed specifically and abundantly in male germ cells. Here we report that the 3' termini of piRNAs are 2'-O-methylated; this modification may have important implications for the biogenesis and function of piRNAs.