MG-SINE - A SHORT INTERSPERSED NUCLEAR-ELEMENT FROM THE RICE BLAST FUNGUS, MAGNAPORTHE-GRISEA

A short interspersed nuclear element, Mg-SINE, was isolated and charac terized from the genome of the rice blast fungus, Magnaporthe grisea. Mg-SINE was isolated as an insertion element within Poll, an inverted- repeat transposon from M. grisea and shows typical features of a mamma lian SINE, Mg-SINE is present as a 0.47-kb interspersed sequence at ap proximate to 100 copies per haploid genome in both rice and non-rice i solates of M. grisea, indicating a common evolutionary origin, Seconda ry structure analysis of Mg-SINE revealed a tRNA-related region at the 5' end which folds into a cloverleaf structure. Genomic fusions resul ting in chimeric Mg-SINEs (Ch-SINEs) composed of a sequence homologous to Mg-SINE at the 3' end and an unrelated sequence at its 5' end were also isolated, indicating that this and other DNA rearrangements medi ated by these elements may have a major effect on the genomic architec ture of this fungus.