A self-stabilizing Ac derivative and its potential for transposon tagging.

With the goal of developing a self-stabilizing transposon tagging system, a derivative of the maize transposable element Ac (Ds303) harbouring a deletion between bp 246 and 736 has been introduced into tomato (Lycopersicon esculentum) by Agrobacterium tumefaciens-mediated transformation. The deletion removes the major transcription start site, 84 bp of the putative Ac promoter and part of the untranslated leader. Transpositions from the T-DNA, where Ds303 was inserted between the mannopine synthase 1' promoter and the GUS gene, were observed in four independent transgenic plants analysed. After transposition the transposed Ds303 elements were stably integrated in the genome and could not transactivate a tester Ds element. However, somatic and germinal transpositions of the transposed Ds303 elements occurred in the presence of a transposase source.