Figure 1.

Diagram showing how a microRNA precursor was divided into zones for scoring. Shown is pre-miR-339. Zone 1 comprises the loop, zone 2 includes the region giving rise to the mature mir-339 sequence (shown in bold), and zone 3 includes sequences (if any) below the mature microRNA. Regions of bases connected by bonds (including G:U bonds) are referred to as stems, and opposing bases not connected by bonds are referred to as bulges.