Table 1.
Transposons in 17.2 Mb of the Arabidopsis thaliana (Columbia) genome
| Type | Superfamily | Number of groups | Number of transposons |
|---|---|---|---|
| Class I | SINEs* | 3 | 16 |
| LINEs† | 28 | 31 | |
| copia-like Retrotransposons | 27 | 40 | |
| gypsy-like Retrotransposons | 23 | 45 | |
| Undetermined‡ | 2 | 2 | |
| Class II | Ac-like | 7 | 38 |
| CACTA-like | 1 | 3 | |
| MULEs | 28 | 108 | |
| MITEs | 15 | 105 | |
| MLEs | 1 | 56 | |
| Class? | Basho | 7 | 179 |
| Total | 142 | 623 |
*
Short interspersed nuclear elements (SINEs) are defined as elements that lack coding capacity or have no similarity to coding regions and have either a putative pol III promoter, a long TSD, and/or a poly A+T-rich tail at one terminus (27, 28).
†
Long interspersed nuclear elements (LINEs) are defined as having members with sequence similarity to the coding domains of previously reported LINEs.
‡
These elements structurally resemble LTR-retrotransposons (i.e., an element with LTRs and 4-bp TSDs but no coding capacity and a putative solo-LTR) but lack signature sequences typical of copia-like or gypsy-like retrotransposons (29).