Meeting Abstract
P1.78 Thursday, Jan. 3 Expression of Thor Increases Desiccation Resistance in Drosophila melanogaster KOBEY, R.L.*; HOSHIZAKI, D.K.; GIBBS, A.G.; University of Nevada, Las Vegas kobeyr@unlv.nevada.edu
The Thor gene codes for the Drosophila melanogaster 4E-binding protein, which binds elongation initiation factor 4E to inhibit mRNA translation. Microarray data reveal that expression of Thor increases 6.5-fold when D. melanogaster is exposed to desiccation. This suggests a role for Thor in response to water stress, possibly by reducing protein synthesis to conserve energy. To test this hypothesis directly, we assayed desiccation resistance in two strains lacking THOR activity and a control strain that expresses active THOR. The THOR-inactive strains included one in which Thor had been knocked out by P-element insertion, and one in which the P-element had been imprecisely removed, thereby disrupting the Thor gene. In the control line the P-element was excised precisely, thereby providing an excellent control for genetic background. Males lacking active THOR survived 6 hours in dry air at 25 oC, whereas the control males survived significantly longer (8.5 hours; ANOVA; P<0.0001). Our results support an important role for THOR (a downstream target of TOR/insulin signaling) in survival of water stress. We have also obtained strains in which Thor expression can be up-regulated by over expression of a Thor transgene or down-regulated by RNA interference using the GAL4/UAS system. Our goal is a proof-of-principle for testing microarray-derived hypotheses for the function of individual genes. Supported by an NIH-INBRE Summer Research Fellowship to RLK (grant number 5 P20 RR016464-06) and NSF award IOS-0719551 to DKH and AGG.
