Project title: Evolution and comparative physiology of neuropeptide signaling: functional analysis of somatostatin- and melanin-concentrating hormone (MCH)-type peptides in echinoderms
Summary: The aim of this project will be to use the common European starfish Asterias rubens as a model system to investigate the evolution and physiological roles of somatostatin/melanin-concentrating hormone (MCH)-type neuropeptide signalling systems. Analysis of neural transcriptome sequence data (RNA-seq; Illumina Hiseq) recently obtained by the Elphick lab has identified 40 neuropeptide precursor genes in Asterias rubens, including a somatostatin-type precursor and a MCH-type precursor. In this project, mass spectroscopic techniques will first be used to identify somatostatin/MCH-type neuropeptides present in nerve cord extracts from Asterias rubens. In vitro assays will be used to identify the G-protein coupled receptors that mediate effects of somatostatin/MCH-type neuropeptides in starfish. Use of mRNA in situ hybridization techniques and/or immunocytochemistry will enable patterns of somatostatin/MCH-type neuropeptide and receptor expression in Asterias rubens to be determined. Then, informed by expression data, the physiological roles of somatostatin/MCH-type neuropeptides will be investigated using in vitro and in vivo pharmacology.
Importantly, this will be the first project to investigate the function of somatostatin/MCH-type neuropeptides in an invertebrate. Therefore, this project will provide important insights on the evolutionary origins of the physiological roles of this class of neuropeptides.