Elucidation of the molecular envenomation strategy of the cone snail Conus geographus through transcriptome sequencing of its venom duct

• Published in: BMC genomics Vol. 13; no. 1; p. 284
• Main Authors: Hu, Hao, Bandyopadhyay, Pradip K, Olivera, Baldomero M, Yandell, Mark
• Format: Journal Article
• Language: English
• Published: London BioMed Central 28.06.2012; BioMed Central Ltd; BMC
• Subjects: Academic libraries; Amino Acid Sequence; Analysis; Animal Genetics and Genomics; Animals; Behavior; Biomedical and Life Sciences; Bites and stings; Calcium channels; Calcium Channels - chemistry; Calcium Channels - metabolism; Cone snails; Conotoxins; Conotoxins - genetics; Conotoxins - metabolism; Contig Mapping; Conus geographus; Conus Snail - genetics; Conus Snail - metabolism; Genetic aspects; Library collections; Life Sciences; Marine; Marine toxins; Microarrays; Microbial Genetics and Genomics; Molecular Sequence Data; Multicellular invertebrate genomic; Neurosciences; Peptides; Physiological aspects; Plant Genetics and Genomics; Prey; Proteins; Proteomics; Receptors, Nicotinic - chemistry; Receptors, Nicotinic - metabolism; Research Article; RNA; RNA, Messenger - metabolism; RNA-seq; Sequence Analysis, DNA; Toxins; Transcriptome - genetics; Venom; Venom duct compartmentalization; Venoms - genetics; Venoms - metabolism; United States; RNA-seq; Venom duct compartmentalization; Conotoxins
• ISSN: 1471-2164; 1471-2164
• DOI: 10.1186/1471-2164-13-284

Background The fish-hunting cone snail, Conus geographus , is the deadliest snail on earth. In the absence of medical intervention, 70% of human stinging cases are fatal. Although, its venom is known to consist of a cocktail of small peptides targeting different ion-channels and receptors, the bulk of its venom constituents, their sites of manufacture, relative abundances and how they function collectively in envenomation has remained unknown. Results We have used transcriptome sequencing to systematically elucidate the contents the C. geographus venom duct, dividing it into four segments in order to investigate each segment’s mRNA contents. Three different types of calcium channel (each targeted by unrelated, entirely distinct venom peptides) and at least two different nicotinic receptors appear to be targeted by the venom. Moreover, the most highly expressed venom component is not paralytic, but causes sensory disorientation and is expressed in a different segment of the venom duct from venoms believed to cause sensory disruption. We have also identified several new toxins of interest for pharmaceutical and neuroscience research. Conclusions Conus geographus is believed to prey on fish hiding in reef crevices at night. Our data suggest that disorientation of prey is central to its envenomation strategy. Furthermore, venom expression profiles also suggest a sophisticated layering of venom-expression patterns within the venom duct, with disorientating and paralytic venoms expressed in different regions. Thus, our transcriptome analysis provides a new physiological framework for understanding the molecular envenomation strategy of this deadly snail.