A guide RNA associated with Piwi-family proteins. Most characterized animal piRNA pathways use Dicer-independent processing of single-stranded precursors; the approximately 21-nucleotide C. elegans 21U RNAs are distinct from the longer typical fly and mammalian piRNAs.[ref]
Specialized piRNA Pathways Act in Germline and Somatic Tissues of the Drosophila Ovary by Colin D. Malone and others. 2009, pp. 522–535, somatic and germline pathway-mutant comparisons
New to topics? Read the docs here!