Fig. 1.

Schematic of the precursor miRNAs derived from repetitive elements (REs) located in the genome. REs and precursor miRNAs are shown as horizontal bold bars and upper thin bars, respectively. The type 1 precursor miRNAs are formed by two adjacent REs (A). Type 2 precursor miRNAs are formed by MADE1 (B), whereas type 3 precursor miRNAs are formed by medium reiterated sequence (MER) (C). The type 4 precursor miRNAs contain RE sequences (D), and the type 5 precursor miRNAs are located between the flanking sequences and REs (E). The type 6 precursor miRNAs are retained within the RE sequences (F).