title: GPCR and IR genes in Schistosoma mansoni miracidia.
abstract: Schistosoma species are responsible for the disease schistosomiasis, a highly prevalent helminthic disease that requires a freshwater snail as intermediate host. The S. mansoni free-living miracidium must utilize olfaction to find a suitable snail host, and certain types of rhodopsin G protein-coupled receptors (GPCRs) and ionotropic receptors (IRs) have been identified as olfactory receptors in other animal phyla. The Schistosoma genome project, together with the recent availability of proteomic databases, allowed for studies to explore receptors within S. mansoni, some of which may contribute to host finding.
  
  
  
  We have identified 17 rhodopsin-type GPCR sequences in S. mansoni belonging to four subclasses, including ligand-specific GPCRs (i.e. neuropeptide and opsin). RT-PCR demonstrated the expression of nine out of the 17 GPCRs in the free-living miracidia, each of which have been characterized for homology to S. haematobium. Among the nine GPCRs, two are predicted as Gq-opsins. We also describe the characterization of a Schistosoma-encoded IR based on similarity with other species IR and conservation of IR-like domains. Schistosoma mansoni IR is expressed in miracidia at 3 and 6 h post-hatch.
  
  
  
  The identification of receptors in S. mansoni miracidia, presented here, contributes not only to further understanding of Schistosoma biology and signal transduction but also provides a basis for approaches that may modify parasite behaviour.
authors: Faculty of Science, Health and Education, University of the Sunshine Coast, Maroochydore, QLD, 4558, Australia.
authors: Di
authors: D
authors: Liang
authors: Faculty of Science, Health and Education, University of the Sunshine Coast, Maroochydore, QLD, 4558, Australia.
authors: Min
authors: M
authors: Zhao
authors: Faculty of Science, Health and Education, University of the Sunshine Coast, Maroochydore, QLD, 4558, Australia.
authors: Tianfang
authors: T
authors: Wang
authors: Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Q4006, Australia.
authors: Donald P
authors: DP
authors: McManus
authors: Faculty of Science, Health and Education, University of the Sunshine Coast, Maroochydore, QLD, 4558, Australia. scummins@usc.edu.au.
authors: Scott F
authors: SF
authors: Cummins
mesh_terms: D000818:Animals; D001700:Biomphalaria / Q000469:parasitology; D017238:Genes, Helminth; D006790:Host-Parasite Interactions; D040901:Proteomics; D043562:Receptors, G-Protein-Coupled / Q000145:classification / Q000235:genetics*; D058468:Receptors, Ionotropic Glutamate / Q000235:genetics*; D012550:Schistosoma mansoni / Q000235:genetics*; D012555:Schistosomiasis mansoni / Q000469:parasitology
chemical_list: D043562:Receptors, G-Protein-Coupled; D058468:Receptors, Ionotropic Glutamate
keywords: Biomphalaria glabrata; G protein-coupled receptor; Ionotropic receptor; Schistosoma mansoni