The effect of ectopic expression of Dorsal and Dif on Drosophila Gene Expression

This study explores the effect of ectopic expression of Dorsal and Dif on Drosophila larval gene expression. The abstract of the manuscript we are submitting follows: Microarray analyses reveal possible new targets for the Rel protein Dif in Drosophila melanogaster The fruit fly Drosophila melanogaster express three closely related NF-κB-like transcription factors: Dorsal, Dif, and Relish. They share significant sequence identity in their DNA binding Rel homology domain and bind similar DNA sequence motifs. These factors play an important role in the transcription of Drosophila humoral immune proteins such as antimicrobial peptides during infection. To study their roles in vivo, we used microarrays to determine the effect of null mutations in individual Rel transcription factors on larval gene expression. Of the 188 genes that were significantly upregulated in wildtype larvae upon bacterial challenge, overlapping but distinct groups of genes were affected in the Rel mutants. We also ectopically expressed Dorsal or Dif and used cDNA microarrays to determine the genes that were up-regulated in the presence of these transcription factors. Combining this data, we identified novel genes that may be specific targets of Dif. Keywords: Genetic Modification Staged larvae containing a transgenic HS-Dorsal or HS-Dif were subjected to 37C for one hour, and their gene expression was compared to wildtype Drosophila treated in the same way. The experiment was repeated in triplicate.