Establishment of a gene tagging system in Arabidopsis thaliana based on the maize transposable element Ac.

An Ac-derived, two-component transposable element system has been developed and analyzed with respect to its use in Arabidopsis thaliana. This system consists of an immobilized Ac element ("Ac clipped wing", Accl) as the source of transactivating transposase and a nonautonomous "Ds" element, DsA, which is inserted into a chimaeric neomycinphosphotransferase gene used as excision marker. After separate introduction of Acc1 and DsA into Arabidopsis thaliana, progeny analysis of crosses between five different Accl lines and seven different DsA lines shows that: (1) different Accl lines differ greatly in their capacity to transactivate DsA; (2) different DsA lines do not differ significantly with respect to DsA transactivation by one Accl line; (3) reintegration of excised DsA elements, both at (genetically) linked and unlinked sites, occurs in about 50% of the excision events; and (4) plants with a high rate of somatic excisions can be used as source of new DsA transpositions, allowing the creation of a large number of independent DsA insertions.