Arpan Ghosh

Research Interests:

BMP Signaling in Drosophila NMJ development:
Bone Morphogenetic Protein (BMP) signaling is crucial for development of the central and peripheral nervous systems in both vertebrates and invertebrates. They regulate cell fate, proliferation, patterning and axon guidance in the developing nervous system in a spatio-temporal fashion. At postnatal stages they are needed for further maturation of the CNS and synapse formation and stabilization. Despite decades of study very few down stream targets of BMP signaling have been identified in the CNS. The pathway acts in a cell type specific and concentration dependent manner making micro array based high throughput analysis extremely difficult. Moreover, there are approximately 10 members of BMP ligands in mammals, which further complicates such studies. The fruit fly Drosophila melanogaster contains only three BMP homologues. They signal through two type I receptors Sax and Tkv in combination with the type II receptors Wit and Punt. BMP signaling has been shown to be involved in the development and functioning of the Drosophila Neuro-Muscular Junction (NMJ) making it an ideal system to study role of BMPs in synaptogenesis and functioning of synapses. The BMP ligand Gbb is released from the muscle and acts on the motorneurons to regulate synaptic function at the NMJ. In addition Gbb regulates the release of several neuropeptides from neurosecretory cells. Mutations in the type II receptor Wit impairs normal Gbb signaling and manifests phenotypes ranging from reduced synaptic efficacy, defects in synaptic morphology and ultra-structure, and impairment in the production of several neuropeptides.

Although the phenotypes of Wit mutants are well characterized, the down stream transcriptional targets of Wit signaling that are responsible for these effects are not known. The goal of my project is to identify using a molecular screen downstream targets of Wit/BMP signaling in the Drosophila motorneuron.