Erect wing regulates synaptic growth in Drosophila by integration of multiple signaling pathways

Irmgard U Haussmann¹ , Kalpana White² and Matthias Soller¹

¹School of Biosciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK

²Department of Biology and Volen Center for Complex Systems, Brandeis University, Waltham, MA 02454, USA

author email corresponding author email

Genome Biology 2008, 9:R73doi:10.1186/gb-2008-9-4-r73


Published:	17 April 2008

Abstract

Background

Formation of synaptic connections is a dynamic and highly regulated process. Little is known about the gene networks that regulate synaptic growth and how they balance stimulatory and restrictive signals.

Results

Here we show that the neuronally expressed transcription factor gene erect wing (ewg) is a major target of the RNA binding protein ELAV and that EWG restricts synaptic growth at neuromuscular junctions. Using a functional genomics approach we demonstrate that EWG acts primarily through increasing mRNA levels of genes involved in transcriptional and post-transcriptional regulation of gene expression, while genes at the end of the regulatory expression hierarchy (effector genes) represent only a minor portion, indicating an extensive regulatory network. Among EWG-regulated genes are components of Wingless and Notch signaling pathways. In a clonal analysis we demonstrate that EWG genetically interacts with Wingless and Notch, and also with TGF-β and AP-1 pathways in the regulation of synaptic growth.

Conclusion

Our results show that EWG restricts synaptic growth by integrating multiple cellular signaling pathways into an extensive regulatory gene expression network.