Evolutional Analysis Of MULEs In The Genus Oryza And Transcription Analysis Of MULEs In The Genus Setaria

The maize Mutator (Mu) system has been described as the most active and mutagenic plant transposon so far discovered. Mu -like elements (MULEs) are widespread among plants. And in several species it is clear that multiple paralogous elements can be present in a single genome. In some species such as wheat (Triticum aestivum) and rice(Oryza sativa), mudrA-similar sequences are represented in cDNA databases, suggesting the presence of active Mu transposon systems in these species. The purpose of the research is to analyze the transcriptional activity of MULEs in the genus Setaria, and to investigate how MULEs evolve in the genus Oryza. Finally, we want to detect the distribution of Os493-likes in the genus Oryza. Main results illustrated as follows:PCR amplification using primer pairs designed to the Conserved regions of mudrA of maize. The materials include 16 Oryza species and 18 accessions of O.rufipogon. The 600bp products were obtained in 15 Oryza species and all the accessions of O.rufipogon. These products were then cloned and sequenced. At last we get 58 clones from 15 Oryza species and 15 clones from 18 accessions of O.rufipogon . The results suggest MULEs are widespread among the the genus Oryza. The alignment of multiple sequences demonstrate the high similarity among the 58 sequences. It is probably due to the transposition activity not long ago. When these sequences are subjected to phylogenetic analysis, they fall into 3 distinct classes.We used specific PCR and Southern blot strategies to find out the the distribution of Os493-likes in the genus Oryza. 3kbp PCR products and blot signals can be found in most of species .These results suggest Os493-likes exist in the genomes of these species. The 3kbp PCR products of O.rufipogon and O.nivara was cloned , then sequenced. The sequences we got have a very high similarity with Os493,so we can conclude there are Os493-likes in the two species.The RT-PCR primers are designed according to FA07-1, MULE in S.faberii and the materials are immature ears of S.italica, S.verticillata and S.viridis. The 360bp products occur in the three species above by RT-PCR. The product in S.verticillata was cloned and sequenced. The analysis of this sequence reveal that this region is transcriptionally active in the immature ears of S.verticillata we used.