Table 2.

The distribution of pre-miRNAs inside introns

Orientation and grouping	Number of pre-miRNAs (%)
DNA strand
Transcribed	179 (86.9 ± 2.4)
Complementary	27 (13.1 ± 2.4)
Pre-miRNA clustering
One per intron	157 (76.2 ± 3.0)
In clusters (≥2)	49 (23.8 ± 3.0)

The data represents intronic pre-miRNA among transcribed and complementary strands as well as the tendency for pre-miRNA to form clusters within introns. A cluster is defined as any intron containing more than one pre-miRNA, irrespective of strand orientation. Percentages are shown ± SE.