Functionality of the GAL4/UAS system in <it>Tribolium </it>requires the use of endogenous core promoters

• Main Authors: Klingler Martin, Averof Michalis, Kiupakis Alexandros, Viktorinova Ivana, Weber Markus, Schinko Johannes B, Wimmer Ernst A, Bucher Gregor
• Format: Article
• Language: English
• Published: BMC 2010-05-01
• Series: BMC Developmental Biology
• Online Access: http://www.biomedcentral.com/1471-213X/10/53

<p>Abstract</p> <p>Background</p> <p>The red flour beetle <it>Tribolium castaneum </it>has developed into an insect model system second only to <it>Drosophila</it>. Moreover, as a coleopteran it represents the most species-rich metazoan taxon which also includes many pest species. The genetic toolbox for <it>Tribolium </it>research has expanded in the past years but spatio-temporally controlled misexpression of genes has not been possible so far.</p> <p>Results</p> <p>Here we report the establishment of the GAL4/UAS binary expression system in <it>Tribolium castaneum</it>. Both GAL4Δ and GAL4VP16 driven by the endogenous heat shock inducible promoter of the <it>Tribolium hsp68 </it>gene are efficient in activating reporter gene expression under the control of the Upstream Activating Sequence (UAS). UAS driven ubiquitous tGFP fluorescence was observed in embryos within four hours after activation while <it>in-situ </it>hybridization against tGFP revealed expression already after two hours. The response is quick in relation to the duration of embryonic development in <it>Tribolium </it>- 72 hours with segmentation being completed after 24 hours - which makes the study of early embryonic processes possible using this system. By comparing the efficiency of constructs based on <it>Tribolium, Drosophila</it>, and artificial core promoters, respectively, we find that the use of endogenous core promoters is essential for high-level expression of transgenic constructs.</p> <p>Conclusions</p> <p>With the established GAL4/UAS binary expression system, ectopic misexpression approaches are now feasible in <it>Tribolium</it>. Our results support the contention that high-level transgene expression usually requires endogenous regulatory sequences, including endogenous core promoters in <it>Tribolium </it>and probably also other model systems.</p>