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", Ac(cl)) as the source of transactivating transposase and a nonautonomous "Ds" element, DS(A), which is inserted into a chimaeric neomycinphosphotransferase gene used as excision marker. After separate introduction of Ac(cl) and DS(A) into Arabidopsis thaliana, progeny analysis of crosses between five different Ac(cl) lines and seven different DS(A) lines, shows that: (1) different Ac(cl) lines differ greatly in their capacity to transactivate Ds(A); (2) different DS(A) lines do not differ significantly with respect to Ds(A) transactivation by one Ac(cl) line; (3) reintegration of excised Ds(A) 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 DS(A) transpositions, allowing the creation of a large number of independent DS(A) insertions.