Table 2. Structures and ages of LTR-retrotransposons identified in orthologous regions of indica and japonica
Structures of LTR-retrotransposons
Number of LTR-retrotransposons
Age,* mya
Range Average
Present in indica only
    Solo LTR 9
    Intact element 4 0.12-0.31 0.22
Present in japonica only
    Solo LTR 8
    Intact element 7 0.00-0.31 0.16
Present in indica and japonica
    Solo LTR 13 and 12
    Intact element 1 and 2 0.69-2.04 1.37
  • * Ages of LTR-retrotransposons were estimated by employing a substitution rate of 1.3 × 10-8 mutations per site per year.

  • Thirteen and 12 of 14 conserved LTR-retrotransposons between indica and japonica have undergone unequal homologous recombination, respectively.