Molecular Cloning And Structure Analysis Of PIF-like Element In Moso Bamboo And The MLE Transposon Effects On Polymorphism Of Moso Bamboo Genome

P instability factor (PIF) was first found in corn DNA transposons, homologous andsame type DNA transposons with similar structure (PIF-like elements) have recently beenallocated to a new and widespread superfamily of DNA transposons called PIF family.This element consists of two open reading frames(ORF), terminal inverted repeats（TIR）and target site duplications (TSDs). Mariner-Like element (MLE) is an important family ofthe super family autonomous Tc1/Mariner transposon. The transposon consists of the TIRsat the ends of transposon, the domian of coding transposase in-between and the TA repeatsequences TSDs result from the new insertion site. MLE transposon, which has threefollowing features: simple transposon structure, nearly random insertional locus oftransposons in genome and high heterologous translocation rate, has been the research hotspot with PIF-like transposon in recent years.A total length of PIF-like transposon (PhPIF-1), in this study, is first isolated frommoso Bamboo by chromosome walking method based on magnetic enrichment procedure.PhPIF-1is5953bp in length, with20bp imperfect inverted terminal repeats and3bp targetsite duplications, and PhPIF-1element consists of two open reading frames, one encodinga putative transposase, including the complete DDE-domain typical of PIF/Harbingerelements from plants, and the other encoding a DNA-binding protein, which has seventermination codons and two frameshift mutations in this open reading frame, so weconclude that PhPIF-1transposon has no translocation activity.Three MLE transposons, obtained by our research group, have complete struction andconservative sequences. We choose the moso bamboos with abundant variation as theexperimental material to detect the polymorphisms of the three transposons’ insertion sitesbased on the SSAP technology. Total356bands, in which160are polymorphic, aredetected, and the ratio of polymorphic is44.9%. Experiments prove that MLE transposonwidely distributed in the genome of bamboo and its variants。Moso bamboo generates many variant during the environment adaptation andintroduction cultivation, such as the leaf colour, stem colour, stem shape and so on, butthese variants can not be inherited steadily and will have back mutation when externalenvironment changes. We conclude that there is some connection between the transposonactivity and the phenotypic changes of moso bamboo, so some polymorphism fragmentswere sequenced and four insertion sites were found to locate inside the genes，this may result in the changes of some genes’ expression pattern, but we didn’t find the direct linkevidence between the bamboo phenotypic changes and the transposon activity.