Table 1 Number of miRNA and host genes (Ensembl, release 77)
| Â | Pig | Human | Mouse | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Â | N | % | % | N | % | % | N | % | % |
miRNA total | 877 | 100.0 | Â | 4272 | 100.0 | Â | 2009 | 100.0 | Â |
  Intergenic | 587 | 66.9 |  | 2132 | 49.9 |  | 900 | 44.8 |  |
  Intragenic | 290 | 33.1 | 100.0 | 2140 | 50.1 | 100.0 | 1109 | 55.2 | 100.0 |
   Host strand | 186 |  | 64.1 | 1482 |  | 69.3 | 825 |  | 74.4 |
   Intron | 166 |  | 57.2 | 1282 |  | 59.5 | 710 |  | 64.0 |
   Exon | 20 |  | 6.9 | 200 |  | 9.3 | 115 |  | 10.4 |
  Opposite strand | 95 |  | 32.8 | 550 |  | 25.7 | 244 |  | 22.0 |
   Intron | 71 |  | 24.5 | 485 |  | 22.7 | 197 |  | 17.8 |
   Exon | 24 |  | 8.3 | 65 |  | 3 | 47 |  | 4.2 |
  With multiple hosts | 9 |  | 3.1 | 108 |  | 5 | 40 |  | 3.6 |
Hosts total | 272 | 100.0 | Â | 1887 | 100.0 | Â | 930 | 100.0 | Â |
  miRNA strand | 173 | 63.6 | 100.0 | 1201 | 63.6 | 100.0 | 646 | 69.5 | 100.0 |
   With intronic miRNA | 155 |  | 89.6 | 1011 |  | 84.2 | 540 |  | 83.6 |
   With exonic miRNA | 18 |  |  | 190 |  |  | 106 |  |  |
  Opposite strand | 82 | 30.1 | 100.0 | 449 | 23.8 | 100.0 | 216 | 23.2 | 100.0 |
   With intronic miRNA | 59 |  | 72.0 | 385 |  | 85.7 | 175 |  | 81.0 |
   With exonic miRNA | 23 |  |  | 64 |  |  | 41 |  |  |
  With multiple miRNAs | 17 | 6.3 |  | 237 | 12.6 |  | 68 | 7.3 |  |