Abstract: The novel germ-line transformation systems disclosed in this patent application allow the physical deletion of transposon DNA following the transformation process, and the targeting of transgene integrations into predefined target sites. In this way, transposasemediated mobilization of genes-of-interest are excluded mechanistically and random genomic integrations eliminated. In contrast to conventional germ-line transformation technology, our systems provide enhanced stability to the transgene insertion. Furthermore, DNA sequences required for the transgene modification (e.g. transformation marker genes, transposase or recombinase target sites), are largely removed from the genome after the final transgene insertion, thereby eliminating the possibility for instability generated by these processes.