Gene Tagging by Activating DNA Transposon nDart in lndica Rice

As International Rice Genome sequencing Project （2005） demonstrated, the rice genome contains various transposons and about 13% of the genome is occupied by DNA transposons. So far, only a few DNA transposons have been reported to be actively transposed. Since transposons are important for gene-functional analysis, it is necessary to explore active transposon source. We identified an active nonautonomous DNA transposon, nDart1-0, belonging to the hAT superfamily in a spontaneous mutable virescent, pyl-v plant. Blast searches in the available databases revealed that Nipponbare and 93-11 carries 13 and 7 nDart1 homologues, respectively, nDart1-0 was found to be transposed most frequently among these homologues. Furthermore, nDart1-0 carries a specific basesubstitution at position 173, and this sequence alteration generates nDart1-0-specific restriction enzyme cleavage site. So, we developed an nDart1-0-specific detection system using iPCR （nl-0SPiPCR）, which should be useful for our nDart1-0-specific tagging system. Since we could not find either any active nDarts or active autonomous element Darts in indica varieties, we tried to introduce japonica-derived nDart1-0 and aDart into indica variety Kasalath by backcrossing. In BC2F2, a mutable chlorophyll mutant was newly generated. Through genetic analysis,

Gene Tagging by Activating DNA Transposon nDart in lndica Rice