Mapping of mRNA cleavage sites by cotton miRNAs using RNA ligase-mediated rapid amplification of 5' complementary DNA ends (RLM 5' RACE). The arrows indicate the 5' ends of miRNA-guided cleavage products, and the numbers indicate the ratios of cleaved products of the total fragments that were sequenced. Only a single cleavage product was observed within the miRNA-complementary region for each examined EST target, except for a miR166 target, in which two products resulting from adjacent sites were detected. The EST targets (from 5' to 3') with accession numbers are shown in the top strand ('+', sense strand orientation; '-', antisense strand), and Gh-miRNAs are shown in the bottom strand with the orientation from 3' (left) to 5' (right). The total lengths of the target ESTs are shown above the EST accession numbers. Wobble U-G pairs are indicated by black dots. Note that Gh-miR166 had two adjacent cleavage sites in the predicted target. ARF, auxin responsive factor.