Cloning and developmental expression of a chick G-protein-coupled receptor SCGPR1

To identify spinal motor neuron subtype-specific transcripts, we employed a single cell subtractive screen of mRNAs in chick embryos. We cloned a differentially expressed gene that termed spinal cord G-protein-coupled receptor 1 (SCGPR1) from its expression pattern that change dynamically in the developing spinal cord. The vertebrate orthologue of SCGPR1 is termed Gpr37 (GPCR/CNS1, ET(B)R-LP-1, Pael-R), however the specific ligand of this receptor has not been identified. Recent studies indicate that Pael-R can associate with parkin, a ubiquitin ligase which accumulates in Lewy bodies in dopaminergic neurons and is associated with Parkinson's disease. Although SCGPR1 (Gpr37) expression has been examined in adult tissues, the embryonic expression has not reported. Here, we have defined the expression pattern of SCGPR1 by in situ hybridization during chick development. SCGPR1 was first detected at HH stage 7 in the neural tube and notochord. As development progressed, SCGPR1 expression became restricted to the ventral neural tube. SCGPR1 expression was also present in the developing telencephalon, mesencephalon, retina, visceral-class motor neurons, myotome and thyroid invagination.