Poster #RP119
Mutator-LIKE TRANSPOSASES IN RICE AND SUGARCANE
Nilo Luiz Saccaro Jr*, Marie-Anne Van Sluys*, Magdalena Rossi*
*Universidade de São Paulo, São Paulo, Brazil
The maize Mutator transposon contains the mudrA gene, which encodes for the MURA transposase. The element is flanked by terminal inverted repeats (TIRs), and target duplication sites (TDSs) that are generated during element insertion. MURA transposase contains two characteristic conserved domains: the DNA binding motif (CX2CX4HX4C), and the transposase active site determined by the triad of acidic amino acids DDE. Comparative studies using MURA-like sequences, identified in genomic and cDNA databases, resulted in the identification of these conserved domains in sugarcane, Arabidopsis thaliana and Oryza sativa, which can be grouped in four classes that arose prior to the monocot/eudicot split. In sugarcane genome, the copy number of mudrA-like sequences greatly differs between classes probably reflecting a different transposicional activity. In order to evaluate the evolutionary history of transposons; a comparative analysis of abundance, genomic distribution and structure of Mutator-like sequences was carried out between rice and sugarcane. Considering ploidy, rice presented a similar copy number for each class, suggesting that class specific amplification preceded species divergence. Genomic structural analysis of rice Mutatorlike loci, such as the presence of TIRs and TSDs, enabled the identification of putatively active elements and gathered clues to facilitate Mutator transposase annotation.