Table 1 Summary of clustered miRNAs in Arabidopsis thaliana , rice ( Oryza sativa ) and poplar ( Populus trichocarpa ) genomes2
| Â | Populus trichocarpa | Oryza sativa | Arabidopsis thaliana |
|---|---|---|---|
Number of clusters with consecutive miRNAs at a distant of (same strand miRNAs): | Â | Â | Â |
   <1 kb | 9 (9) | 16 (14) | 10 (8) |
   <3 kb | 14 (14) | 16 (14) | 13 (11) |
   <10 kb | 20 (20) | 24 (22) | 18 (16) |
% of clustered miRNAs (number of clustered miRNAs/total miRNAs) | 20% (47/234) | 19% (68/353) | 22% (42/187) |
Maximal number of miRNAs encoded in a cluster (cluster size) | 4 (4,593 bp) | 8 (497 bp) | 6 (5,522 bp) |
% of clusters with (number/total of <10 kb miRNA clusters): | Â | Â | Â |
   A single miRNA family | 90% (18/20) | 75% (18/24) | 61% (11/18) |
   Conserved miRNAs | 90% (18/20) | 54% (13/24) | 44% (8/18) |