ABSTRACT: Diversity of conopeptides and conoenzymes from the venom duct of the marine cone snail Conus bayani using transcriptomic and proteomic analyses
Project description:The venom of cone snails is highly variable both between and within species, as well as spatially along the venom duct. However, defferences of defensive and predatory venoms in "hook-and-line" fish hunting clades and their venom duct origins has not been investigated. In this study a combination of proteomics and transcriptomic approaches were used to decode the venom profiles of C. striatus from the Pionoconus clade. The raw data files obtained from the reduced alkylated and digested venom duct sections (distal, central and proximal), injected predatory and defensive induced venoms are submitted here.
Project description:Marine cone snails have attracted researchers from all disciplines but early life stages have received limited attention due to difficulties accessing or rearing juvenile specimens. Here, we document the culture of Conus magus from eggs through metamorphosis to reveal dramatic shifts in predatory feeding behaviour between post-metamorphic juveniles and adult specimens. Adult C. magus capture fish using a set of paralytic venom peptides combined with a hooked radular tooth used to tether envenomed fish. In contrast, early juveniles feed exclusively on polychaete worms using a unique “sting-and-stalk” foraging behaviour facilitated by short, unbarbed radular teeth and a distinct venom repertoire that induces hypoactivity in prey. Our results demonstrate how coordinated morphological, behavioural and molecular changes facilitate the shift from worm- to fish-hunting in C. magus, and showcase juvenile cone snails as a rich and unexplored source of novel venom peptides for ecological, evolutionary and biodiscovery studies.
Project description:Elucidation of the molecular envenomation strategy of the cone snail Conus geographus through transcriptome sequencing of its venom duct
Project description:Combined Proteomic and Transcriptomic Interrogation of the Venom Gland of Conus geographus Uncovers Novel Components and Functional Compartmentalization
Project description:Venomous animals have evolved diverse molecular mechanisms to incapacitate prey and defend against predators. The majority of venom components characterized to date disrupt the nervous, locomotor, and cardiovascular system or causes tissue damage and degradation. The discovery that certain species of fish-hunting cone snail use weaponized insulins to induce hypoglycemic shock in prey provided an unusual example for the use of toxins that target glucose homeostasis. Here, we show that, in addition to insulins, the deadly fish hunter, Conus geographus, uses a selective agonist of the somatostatin receptor 2 (SSTR2) that potently blocks the release of the insulin-counteracting hormone glucagon, thereby exacerbating insulin-induced hypoglycemia in prey. The native toxin, Consomatin nG1, exists in several proteoforms that contain a minimized vertebrate somatostatin-like core motif connected to a heavily glycosylated N-terminal region. We demonstrate that the toxin’s N-terminal tail aligns with a glycosylated somatostatin peptide previously identified from fish pancreas and plays an important role in activating the fish SSTR2. Collectively, these findings provide a stunning example of chemical mimicry, highlight the combinatorial nature of venom components, and establish glucose homeostasis as an effective target for prey capture.
Project description:Venomous animals have evolved diverse molecular mechanisms to incapacitate prey and defend against predators. The majority of venom components characterized to date disrupt the nervous, locomotor, and cardiovascular system or causes tissue damage and degradation1. The discovery that certain species of fish-hunting cone snail use weaponized insulins to induce hypoglycemic shock in prey provided an unusual example for the use of toxins that target glucose homeostasis2. Here, we show that, in addition to insulins, the deadly fish hunter, Conus geographus, uses a selective agonist of the somatostatin receptor 2 (SSTR2) that potently blocks the release of the insulin-counteracting hormone glucagon, thereby exacerbating insulin-induced hypoglycemia in prey. The native toxin, Consomatin nG1, exists in several proteoforms that contain a minimized vertebrate somatostatin-like core motif connected to a heavily glycosylated N-terminal region. We demonstrate that the toxin’s N-terminal tail aligns with a glycosylated somatostatin peptide previously identified from fish pancreas and plays an important role in activating the fish SSTR2. Collectively, these findings provide a stunning example of chemical mimicry, highlight the combinatorial nature of venom components, and establish glucose homeostasis as an effective target for prey capture.
Project description:In order to provide a global insight on the transcripts expressed in the venom gland of the Brazilian ant species Tetramorium bicarinatum and to unveil the potential of its products, high-throughput expressed sequence tags were generated using Illumina paired-end sequencing technology. A total of 212,371,758 pairs of quality-filtered, 100-base-pair Illumina reads were obtained. The de novo assemblies yielded 36,042 contigs for which 27,873 have at least one predicted ORF among which 59.77% produce significant hits in the available databases. The investigation of the reads mapping toxin class revealed a high diversification with the major part consistent with the classical hymenopteran venom protein signature represented by venom allergen (33.3%) followed by a diverse toxin-expression profile including several distinct isoforms of phospholipase A1 and A2, venom serine protease, hyaluronidase, protease inhibitor and secapin. Moreover, our results revealed for the first time the presence of toxin-like peptides that have been previously identified from unrelated venomous animals such as waprin-like (snakes) and agatoxins (spiders and conus). 300 ant specimens from the species Tetramorium bicarinatum were dissected in order to extract the RNA from their venom gland, The whole ant body was used as a reference,
Project description:In order to provide a global insight on the transcripts expressed in the venom gland of the Brazilian ant species Tetramorium bicarinatum and to unveil the potential of its products, high-throughput expressed sequence tags were generated using Illumina paired-end sequencing technology. A total of 212,371,758 pairs of quality-filtered, 100-base-pair Illumina reads were obtained. The de novo assemblies yielded 36,042 contigs for which 27,873 have at least one predicted ORF among which 59.77% produce significant hits in the available databases. The investigation of the reads mapping toxin class revealed a high diversification with the major part consistent with the classical hymenopteran venom protein signature represented by venom allergen (33.3%) followed by a diverse toxin-expression profile including several distinct isoforms of phospholipase A1 and A2, venom serine protease, hyaluronidase, protease inhibitor and secapin. Moreover, our results revealed for the first time the presence of toxin-like peptides that have been previously identified from unrelated venomous animals such as waprin-like (snakes) and agatoxins (spiders and conus).
Project description:Venoms from marine animals have been recognized as a new emerging source of peptide-based therapeutics. Several peptide toxins from sea anemone have been investigated as therapeutic leads or pharmacological tools. Venom complexity should be further confirmed using novel strategies of large-scale sequencing which integrated transcriptomics and proteomics to provide new putative proteins or peptides to be compared among species. We applied transcriptomic combining with proteomic analyses and identified six groups of peptide toxins including neurotoxin, hemostatic and hemorrhagic toxin, protease inhibitor, mixed function enzymes, venom auxiliary proteins, and peptides related to allergen and innate immunity.