Structure of LTR Retroelements Identified in Arabidopsis
| Structure | No. of elements | Mechanism |
| Intact elements | 87 | |
| Solo LTRs | 101 | Intra-element unequal recombination |
| Intact elements without DR | 1 | Intra-element unequal recombination |
| Solo LTRs without DR | 1 | Intra-element unequal recombination |
| Recombined elements contain an LTR flanked by both PBS and PPT | 3a | Intra-element unequal recombination |
| 3′ LTR deleted | 26 | Illegitimate recombination |
| 5′ LTR deleted | 48 | Illegitimate recombination |
| 5′ and/or 3′ LTR partially deleted | 24 | Illegitimate recombination |
[i] One element appears to be the result of two inter-element unequal homologous recombination events in which the 5′ and 3′ LTRs of an element recombined with the 3′ LTR of an upstream element, and the 5′ LTR of a downstream element, respectively.
[ii] LTR, long terminal repeat; PBS, primer-binding site; PPT, polypurine tract; DR, direct repeat.