Footprints or DNA sequence rearrangements left at the donor site following transposition provide clues to the repair mechanisms [3], [5], [6].
Intensive TE transposition provides an explanation for the "C-value paradox", i.e. the fact that in eukaryotes, genome size is not correlated to the complexity of the organism, or to the gene number [ 24].
In this context, transgenesis protocols based on Sleeping Beauty or piggyBac transposition providing the transposase in the form of mRNA have been validated in many eukaryotic species, including mouse and rat models [ 7- 9], and in cultured human cells [ 10].
The large number of transposases in A1501 indicated that this strain would be more suitable for transposition, providing clues to the genetic diversity within this species and its adaptability to changes in growth conditions.
These duplication or transposition events provided a basis for expression divergence.
Because mPing has no coding capacity, the transposase (TPase) required to catalyze its transposition is provided in trans by related autonomous element(s) [ 3, 12, 16].
The mini-Tn7 element on the pFastBac1 donor plasmid was transposed to the mini-attTn7 target site on the bacmid in the presence of transposition proteins provided by the helper plasmid.
Our previous studies suggested that the main contribution of Ds exonization to gene diversity is, based on a single transposition event, providing different splice donors for different reading frames rather than providing genetic messages (Huang et al., 2012).
Based on these observations, the authors proposed that SIR might play an important role in MSITE transposition by providing key motifs.
