title: Transposition and target preferences of an active nonautonomous DNA transposon nDart1 and its relatives belonging to the hAT superfamily in rice.
abstract: The nonautonomous nDart1 element in the hAT superfamily is one of a few active DNA transposons in rice. Its transposition can be induced by crossing with a line containing an active autonomous element, aDart1, and stabilized by segregating aDart1. No somaclonal variation should occur in nDart1-promoted gene tagging because no tissue culture is involved in nDart1 activation. By transposon display analysis, we examined the activities of nDart1-related elements in the selfed progeny of a mutable virescent pyl-v plant containing aDart1. Although various nDart1-related elements are present in the rice genome, only nDart1-3 subgroup elements, nDart1-0 and nDart1-3 in particular, were found to be transposed frequently and integrated into various sites almost all over the genome, and a fraction of the transposed elements were found to be transmitted to the next generation. More than half of the newly integrated elements were identified as nDart1-0. Analysis of the newly inserted sites revealed that the nDart1-3 subgroup elements were predominantly integrated into single-copy regions. More than 60% of the transposed elements were inserted into the genic regions that comprise putative coding regions and their 0.5-kb flanking segments, and approximately two-thirds of them were within the 0.5-kb area in front of the putative initiation codons, i.e., promoter-proximal genic regions. These characteristic features of nDart1-3 subgroup elements seem to be suitable for developing an efficient and somaclonal variation-free gene tagging system for rice functional genomics.
authors.affiliation: National Institute for Basic Biology, Nishigonaka 38, Myodaiji, Okazaki, Aichi, 444-8585, Japan.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Takagi
authors.forename: Masahiko
authors.initials: M
authors.lastname: Maekawa
authors.forename: Kazuo
authors.initials: K
authors.lastname: Tsugane
authors.forename: Shigeru
authors.initials: S
authors.lastname: Iida
mesh_terms: D032461:Chromosomes, Plant; D004251:DNA Transposable Elements; D018744:DNA, Plant / Q000235:genetics*; D018745:Genome, Plant; D012275:Oryza / Q000235:genetics*
chemical_list: D004251:DNA Transposable Elements; D018744:DNA, Plant