 siRNAs derived from long dsRNA precursors differ from miRNAs in that miRNAs , especially those in animals , typically have incomplete base pairing to a target and inhibit the translation of many different mRNAs with similar sequences . In contrast , siRNAs typically base @-@ pair perfectly and induce mRNA cleavage only in a single , specific target . In Drosophila and C. elegans , miRNA and siRNA are processed by distinct argonaute proteins and dicer enzymes . 
