Location

University of Nevada Las Vegas, Student Union Ball Room

Start Date

6-8-2008 9:00 AM

End Date

6-8-2008 12:00 PM

Description

Using microarray analysis of Drosophila melanogaster, the Gibbs lab has identified several hundred candidate genes that may be involved in desiccation resistance. One of these genes is Thor, an important downstream target of the TOR/insulin signaling pathway. Preliminary results confirm that Thor plays a role in desiccation resistance. Further research will be needed to verify these results and understand the mechanism by which Thor increases desiccation resistance. This research will also serve as a proof-of-principle for testing microarray-derived hypotheses.

A previous microarray analysis found evidence that down-regulation of protein synthesis might be a cellular response to desiccation through the up-regulation of Thor. When Drosophila melanogaster adult males are exposed to desiccation, Thor expression increases 6.5-fold. Thor codes for the D. melanogaster 4Ebinding protein (4E-BP), which inhibits translation by binding to the eukaryotic initiation factor 4E (eIF-4E). Thus, a reduction in protein synthesis might function to reduce energy expenditures during desiccation. To test whether THOR plays a role in the response to desiccation, we measured desiccation resistance in flies with altered Thor expression. We measured desiccation resistance in flies with Thor expression reduced through P-element mutagenesis (Thork13517 and Thor2) and RNA interference (RNAi). Using the GAL4/UAS system (Brand and Perrimon, 1993), desiccation resistance was also measured in flies with increased expression of wild-type Thor and constitutively-active Thor (4EBP( AA)). We found that Thor hypomorph mutant males (Thork13517) are desiccation sensitive. However, we found no difference in desiccation sensitivity between Thor null mutants (Thor2) and control flies (Thor1rv1). Knocking down expression of Thor with RNAi increased desiccation sensitivity. However, desiccation resistance did not increase in male flies that over-expressed Thor or a constitutively-active Thor (4E-BP(AA)) using the GAL4/UAS system. These mixed results do not support the hypothesis that Thor expression increases desiccation resistance.

Keywords

Drosophila melanogaster; Fruit flies; Genetic research; Thor genes

Disciplines

Genetics | Molecular Genetics

Language

English

Comments

Abstract & poster


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Aug 6th, 9:00 AM Aug 6th, 12:00 PM

Expression of Thor does not increase desiccation resistance in Drosophila melanogaster

University of Nevada Las Vegas, Student Union Ball Room

Using microarray analysis of Drosophila melanogaster, the Gibbs lab has identified several hundred candidate genes that may be involved in desiccation resistance. One of these genes is Thor, an important downstream target of the TOR/insulin signaling pathway. Preliminary results confirm that Thor plays a role in desiccation resistance. Further research will be needed to verify these results and understand the mechanism by which Thor increases desiccation resistance. This research will also serve as a proof-of-principle for testing microarray-derived hypotheses.

A previous microarray analysis found evidence that down-regulation of protein synthesis might be a cellular response to desiccation through the up-regulation of Thor. When Drosophila melanogaster adult males are exposed to desiccation, Thor expression increases 6.5-fold. Thor codes for the D. melanogaster 4Ebinding protein (4E-BP), which inhibits translation by binding to the eukaryotic initiation factor 4E (eIF-4E). Thus, a reduction in protein synthesis might function to reduce energy expenditures during desiccation. To test whether THOR plays a role in the response to desiccation, we measured desiccation resistance in flies with altered Thor expression. We measured desiccation resistance in flies with Thor expression reduced through P-element mutagenesis (Thork13517 and Thor2) and RNA interference (RNAi). Using the GAL4/UAS system (Brand and Perrimon, 1993), desiccation resistance was also measured in flies with increased expression of wild-type Thor and constitutively-active Thor (4EBP( AA)). We found that Thor hypomorph mutant males (Thork13517) are desiccation sensitive. However, we found no difference in desiccation sensitivity between Thor null mutants (Thor2) and control flies (Thor1rv1). Knocking down expression of Thor with RNAi increased desiccation sensitivity. However, desiccation resistance did not increase in male flies that over-expressed Thor or a constitutively-active Thor (4E-BP(AA)) using the GAL4/UAS system. These mixed results do not support the hypothesis that Thor expression increases desiccation resistance.