title: An active DNA transposon nDart causing leaf variegation and mutable dwarfism and its related elements in rice.
abstract: While characterized mutable alleles caused by DNA transposons have been abundant in maize since the discovery of Dissociation conferring variegation by Barbara McClintock, only a few mutable alleles have been described in rice even though the rice genome contains various transposons. Here, we show that a spontaneous mutable virescent allele, pyl-v, is caused by the disruption of the nuclear-coded essential chloroplast protease gene, OsClpP5, due to insertion of a 607-bp non-autonomous DNA transposon, non-autonomous DNA-based active rice transposon one (nDart1), belonging to the hAT superfamily. The transposition of nDart1 can be induced by crossing with a line containing an autonomous element, aDart, and stabilized by segregating out of aDart. We also identified a novel mutable dwarf allele thl-m caused by an insertion of nDart1. The japonica cultivar Nipponbare carries no aDart, although it contains epigenetically silenced Dart element(s), which can be activated by 5-azacytidine. Nipponbare bears four subgroups of about 3.6-kb Dart-like sequences, three of which contain potential transposase genes, and around 3.6-kb elements without an apparent transposase gene, as well as three subgroups of about 0.6-kb nDart1-related elements that are all internal deletions of the Dart-like sequences. Both nDart1 and 3.6-kb Dart-like elements were also present in indica varieties 93-11 and Kasalath. nDart1 appears to be the most active mutagen among nDart1-related elements contributing to generating natural variations. A candidate for an autonomous element, aDart, and a possible application of nDart1 for transposon tagging are discussed.
authors.affiliation: National Institute for Basic Biology, Okazaki 444-8585, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Tsugane
authors.forename: Masahiko
authors.initials: M
authors.lastname: Maekawa
authors.forename: Kyoko
authors.initials: K
authors.lastname: Takagi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takahara
authors.forename: Qian
authors.initials: Q
authors.lastname: Qian
authors.forename: Chang-Ho
authors.initials: CH
authors.lastname: Eun
authors.forename: Shigeru
authors.initials: S
authors.lastname: Iida
mesh_terms: D000483:Alleles; D001483:Base Sequence; D004251:DNA Transposable Elements; D018744:DNA, Plant; D009154:Mutation; D012275:Oryza / Q000235:genetics* / Q000254:growth & development; D018515:Plant Leaves; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D004251:DNA Transposable Elements; D018744:DNA, Plant