Diversity and structure of PIF/Harbinger-like elements in the genome of Medicago truncatula.

摘要: Transposable elements constitute a significant fraction of plant genomes. The PIF/Harbinger superfamily includes DNA transposons (class II elements) carrying terminal inverted repeats and producing 3 bp target site duplication upon insertion. presence an ORF coding for the DDE/DDD transposase, required transposition, is characteristic autonomous PIF/Harbinger-like elements. Based on above features, were identified in several genomes divided into evolutionary lineages. Availability portion Medicago truncatula genomic sequence allowed mining elements, starting from single previously described element MtMaster. Twenty two putative autonomous, i.e. TPase complete repeats, 67 non-autonomous found genome M. truncatula. They five families, MtPH-A5, MtPH-A6, MtPH-D,MtPH-E, MtPH-M, corresponding to three new largest MtPH-A6 MtPH-M further four subfamilies, respectively. Non-autonomous usually direct deletion derivatives element, however other types rearrangements, including inversions nested insertions also observed. An interesting structural – 60 tandem was observed group subfamily MtPH-A6-4. Some families could be related miniature repeat (MITEs). empty loci (RESites), paralogous those flanking transposable both non-autonomous, as well transposon insertion size polymorphisms, confirmed that some mined capable transposition. population diverse. A detailed intra-family comparison elements' structure proved they proliferated generally following model abortive gap repair. However, facilitated more pronounced rearrangements internal regions. polymorphism MtPH MITE different populations truncatula, if experimentally, used source molecular markers complementary marker systems.