title: Ionotropic Receptors Identified within the Tentacle of the Freshwater Snail Biomphalaria glabrata, an Intermediate Host of Schistosoma mansoni.
abstract: Biomphalaria glabrata (B. glabrata) is an air-breathing aquatic mollusc found in freshwater habitats across the Western Hemisphere. It is most well-known for its recognized capacity to act as a major intermediate host for Schistosoma mansoni, the human blood fluke parasite. Ionotropic receptors (IRs), a variant family of the ionotropic glutamate receptors (iGluR), have an evolutionary ancient function in detecting odors to initiate chemosensory signaling. In this study, we applied an array of methods towards the goal of identifying IR-like family members in B. glabrata, ultimately revealing two types, the iGluR and IR. Sequence alignment showed that three ligand-binding residues are conserved in most Biomphalaria iGluR sequences, while the IRs did exhibit a variable pattern, lacking some or all known glutamate-interactingresidues, supporting their distinct classification from the iGluRs. We show that B. glabrata contains 7 putative IRs, some of which are expressed within its chemosensory organs. To further investigate a role for the more ancient IR25a type in chemoreception, we tested its spatial distribution pattern within the snail cephalic tentacle by in situ hybridization. The presence of IR25a within presumptive sensory neurons supports a role for this receptor in olfactory processing, contributing to our understanding of the molecular pathways that are involved in Biomphalaria olfactory processing.
authors.affiliation: Faculty of Science, Health and Education, University of the Sunshine Coast, Maroochydore, Queensland 4558, Australia.
authors.forename: Di
authors.initials: D
authors.lastname: Liang
authors.affiliation: Faculty of Science, Health and Education, University of the Sunshine Coast, Maroochydore, Queensland 4558, Australia.
authors.forename: Tianfang
authors.initials: T
authors.lastname: Wang
authors.affiliation: Faculty of Science, Health and Education, University of the Sunshine Coast, Maroochydore, Queensland 4558, Australia.
authors.forename: Bronwyn A
authors.initials: BA
authors.lastname: Rotgans
authors.affiliation: Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, 4006, Australia.
authors.forename: Donald P
authors.initials: DP
authors.lastname: McManus
authors.affiliation: Faculty of Science, Health and Education, University of the Sunshine Coast, Maroochydore, Queensland 4558, Australia.
authors.forename: Scott F
authors.initials: SF
authors.lastname: Cummins
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001700:Biomphalaria / Q000235:genetics* / Q000469:parasitology; D005618:Fresh Water; D006790:Host-Parasite Interactions / Q000235:genetics*; D006801:Humans; D058468:Receptors, Ionotropic Glutamate / Q000235:genetics* / Q000302:isolation & purification; D012550:Schistosoma mansoni / Q000235:genetics / Q000472:pathogenicity; D012555:Schistosomiasis mansoni / Q000235:genetics* / Q000469:parasitology; D016415:Sequence Alignment
chemical_list: D058468:Receptors, Ionotropic Glutamate