The genome of Tribolium castaneum (Tc) has been sequenced, and a final assembly is nearly finished (HGSC, Baylor College of Medicine, June 2005). A hybridization-based germline transformation system has been developed for random insertional mutagenesis to facilitate systematic, functional analysis of this genome. The system utilizes transgenic helper and donor strains. Donors carry piggyBac elements marked by either EGFP or Tc vermilion (Tcv), while helpers carry Minos elements marked by DsRed and encode piggyBac transposase, required to catalyze mobilization of the donor element. Remobilization, induced by the hybridization of donor and helper lines, is detected by a change in either expression pattern (EGFP) or expression level (Tcv). To improve the hybridization-based system, we are developing additional helper lines. Our goal is twofold, first to produce an extremely active helper capable of yielding high levels of multiple insertions, and second to produce high levels of single insertion events. To pursue these goals we generated and are testing two promoters to drive piggyBac transposase in the helper, namely those derived from the highly expressed Tc Polyubiquitin gene and a Tc alpha tubulin gene. Data generated from these helper constructs, Tc Polyubiquitin-piggyBac transposase and Tc alpha tubulin-piggyBac transposase, will be presented.