title: The role of defensive ecological interactions in the evolution of conotoxins.
abstract: Venoms comprise of complex mixtures of peptides evolved for predation and defensive purposes. Remarkably, some carnivorous cone snails can inject two distinct venoms in response to predatory or defensive stimuli, providing a unique opportunity to study separately how different ecological pressures contribute to toxin diversification. Here, we report the extraordinary defensive strategy of the Rhizoconus subgenus of cone snails. The defensive venom from this worm-hunting subgenus is unusually simple, almost exclusively composed of αD-conotoxins instead of the ubiquitous αA-conotoxins found in the more complex defensive venom of mollusc- and fish-hunting cone snails. A similarly compartmentalized venom gland as those observed in the other dietary groups facilitates the deployment of this defensive venom. Transcriptomic analysis of a Conus vexillum venom gland revealed the αD-conotoxins as the major transcripts, with lower amounts of 15 known and four new conotoxin superfamilies also detected with likely roles in prey capture. Our phylogenetic and molecular evolution analysis of the αD-conotoxins from five subgenera of cone snails suggests they evolved episodically as part of a defensive strategy in the Rhizoconus subgenus. Thus, our results demonstrate an important role for defence in the evolution of conotoxins.
authors.affiliation: Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, 4072, Australia.
authors.forename: J R
authors.initials: JR
authors.lastname: Prashanth
authors.affiliation: Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, 4072, Australia.|Institut des Biomolécules Max Mousseron, UMR 5247, Université Montpellier-CNRS, Place Eugène Bataillon, 34095, Montpellier Cedex 5, France.
authors.forename: S
authors.initials: S
authors.lastname: Dutertre
authors.affiliation: Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, 4072, Australia.
authors.forename: A H
authors.initials: AH
authors.lastname: Jin
authors.affiliation: Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, 4072, Australia.
authors.forename: V
authors.initials: V
authors.lastname: Lavergne
authors.affiliation: Pathology, Mater Health Services, Raymond Terrace, South Brisbane, Qld, 4101, Australia.|Mater Research Institute, The University of Queensland, St. Lucia, Qld, 4072, Australia.
authors.forename: B
authors.initials: B
authors.lastname: Hamilton
authors.affiliation: Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, 4072, Australia.
authors.forename: F C
authors.initials: FC
authors.lastname: Cardoso
authors.affiliation: ACRF Microscopy Facility, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, 4072, Australia.
authors.forename: J
authors.initials: J
authors.lastname: Griffin
authors.affiliation: Pathology, Mater Health Services, Raymond Terrace, South Brisbane, Qld, 4101, Australia.|Mater Research Institute, The University of Queensland, St. Lucia, Qld, 4072, Australia.|School of Medicine, The University of Queensland, Brisbane, Qld, 4072, Australia.
authors.forename: D J
authors.initials: DJ
authors.lastname: Venter
authors.affiliation: Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, 4072, Australia.
authors.forename: P F
authors.initials: PF
authors.lastname: Alewood
authors.affiliation: Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, 4072, Australia.
authors.forename: R J
authors.initials: RJ
authors.lastname: Lewis
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001315:Australia; D002460:Cell Line; D020916:Conotoxins / Q000737:chemistry* / Q000235:genetics; D052078:Conus Snail / Q000235:genetics*; D019143:Evolution, Molecular; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D017423:Sequence Analysis, RNA; D053719:Tandem Mass Spectrometry; D059467:Transcriptome
chemical_list: D020916:Conotoxins
keywords: conotoxins; defence; evolution; predator-prey interactions; venomics; venoms