Experimental identification of microRNA targets

microRNAs are small RNAs that regulate protein synthesis post-transcriptionally. Animal microRNAs recognize their targets by incomplete base pairing to sequence motifs most often present in the 3' untranslated region of their target mRNAs. This partial complementarity vastly expands the repertoire of potential targets and constitutes a problem for computational target prediction. Although computational analyses have shed light on important aspects of microRNA target recognition, several questions remain regarding how microRNAs can recognize and regulate their targets. Forward experimental approaches allow for an unbiased study of microRNA target recognition and may unveil novel, rare or uncommon target binding patterns. In this review we focus on animal microRNAs and the experimental approaches that have been described for identification of their targets.