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• W2132785801 abstract "Venom is a key innovation underlying the evolution of advanced snakes (Caenophidia). Despite this, very little is known about venom system structural diversification, toxin recruitment event timings, or toxin molecular evolution. A multidisciplinary approach was used to examine the diversification of the venom system and associated toxins across the full range of the ∼100 million-year-old advanced snake clade with a particular emphasis upon families that have not secondarily evolved a front-fanged venom system (∼80% of the 2500 species). Analysis of cDNA libraries revealed complex venom transcriptomes containing multiple toxin types including three finger toxins, cobra venom factor, cysteine-rich secretory protein, hyaluronidase, kallikrein, kunitz, lectin, matrix metalloprotease, phospholipase A2, snake venom metalloprotease/a disintegrin and metalloprotease, and waprin. High levels of sequence diversity were observed, including mutations in structural and functional residues, changes in cysteine spacing, and major deletions/truncations. Morphological analysis comprising gross dissection, histology, and magnetic resonance imaging also demonstrated extensive modification of the venom system architecture in non-front-fanged snakes in contrast to the conserved structure of the venom system within the independently evolved front-fanged elapid or viperid snakes. Further, a reduction in the size and complexity of the venom system was observed in species in which constriction has been secondarily evolved as the preferred method of prey capture or dietary preference has switched from live prey to eggs or to slugs/snails. Investigation of the timing of toxin recruitment events across the entire advanced snake radiation indicates that the evolution of advanced venom systems in three front-fanged lineages is associated with recruitment of new toxin types or explosive diversification of existing toxin types. These results support the role of venom as a key evolutionary innovation in the diversification of advanced snakes and identify a potential role for non-front-fanged venom toxins as a rich source for lead compounds for drug design and development. Venom is a key innovation underlying the evolution of advanced snakes (Caenophidia). Despite this, very little is known about venom system structural diversification, toxin recruitment event timings, or toxin molecular evolution. A multidisciplinary approach was used to examine the diversification of the venom system and associated toxins across the full range of the ∼100 million-year-old advanced snake clade with a particular emphasis upon families that have not secondarily evolved a front-fanged venom system (∼80% of the 2500 species). Analysis of cDNA libraries revealed complex venom transcriptomes containing multiple toxin types including three finger toxins, cobra venom factor, cysteine-rich secretory protein, hyaluronidase, kallikrein, kunitz, lectin, matrix metalloprotease, phospholipase A2, snake venom metalloprotease/a disintegrin and metalloprotease, and waprin. High levels of sequence diversity were observed, including mutations in structural and functional residues, changes in cysteine spacing, and major deletions/truncations. Morphological analysis comprising gross dissection, histology, and magnetic resonance imaging also demonstrated extensive modification of the venom system architecture in non-front-fanged snakes in contrast to the conserved structure of the venom system within the independently evolved front-fanged elapid or viperid snakes. Further, a reduction in the size and complexity of the venom system was observed in species in which constriction has been secondarily evolved as the preferred method of prey capture or dietary preference has switched from live prey to eggs or to slugs/snails. Investigation of the timing of toxin recruitment events across the entire advanced snake radiation indicates that the evolution of advanced venom systems in three front-fanged lineages is associated with recruitment of new toxin types or explosive diversification of existing toxin types. These results support the role of venom as a key evolutionary innovation in the diversification of advanced snakes and identify a potential role for non-front-fanged venom toxins as a rich source for lead compounds for drug design and development. It has only become evident recently that venom in snakes is a basal characteristic and that the three front-fanged venom delivery system architectures are each independent secondary derivations (1Vidal N. Colubroid systematics: evidence for an early appearance of the venom apparatus followed by extensive evolutionary tinkering.J. Toxicol. Toxin Res. 2002; 21: 21-41Crossref Scopus (89) Google Scholar, 2Fry B.G. Lumsden N. Wüster W. Wickramaratna J. Hodgson W.C. Kini R.M. Isolation of a neurotoxin (α-colubritoxin) from a ‘non-venomous’ colubrid: evidence for early origin of venom in snakes.J. Mol. Evol. 2003; 57: 446-452Crossref PubMed Scopus (125) Google Scholar, 3Fry B.G. Wüster W. Assembling an arsenal: origin and evolution of the snake venom proteome inferred from phylogenetic analysis of toxin sequences.Mol. Biol. Evol. 2004; 21: 870-883Crossref PubMed Scopus (190) Google Scholar, 4Fry B.G. Vidal N. Norman J.A. Vonk F.J. Scheib H. Ramjan R. Kuruppu S. Fung K. Hedges S.B. Richardson M.K. Hodgson W.C. Ignjatovic V. Summerhayes R. Kochva E. Early evolution of the venom system in lizards and snakes.Nature. 2006; 439: 509-632Crossref Scopus (448) Google Scholar). In earlier schemes, the “colubrid,” or “non-front-fanged,” snakes were seen as a monophyletic transitional group to the presumably advanced front-fanged lineages Atractaspis, Elapidae, and Viperidae (e.g. Kardong (5Kardong K. Evolutionary patterns in advanced snakes.Am. Zool. 1980; 20: 269-282Crossref Scopus (45) Google Scholar)), and all front-fanged snakes were assumed to share a common ancestor. Resolution of higher order relationships revealed not only the colubrid snakes to be paraphyletic but the front-fanged snakes to be polyphyletic with viperids being one of the earliest advanced snake radiations and elapids only recently derived (1Vidal N. Colubroid systematics: evidence for an early appearance of the venom apparatus followed by extensive evolutionary tinkering.J. Toxicol. Toxin Res. 2002; 21: 21-41Crossref Scopus (89) Google Scholar, 6Vidal N. Delmas A.S. David P. Cruaud C. Couloux A. Hedges S.B. The phylogeny and classification of caenophidian snakes inferred from seven nuclear protein-coding genes.C. R. Biol. 2007; 330: 182-187Crossref PubMed Scopus (172) Google Scholar). Previous studies indicate significant morphological variation in the venom gland (7Taub A.M. Comparative histological studies on Duvernoy's gland of colubrid snakes.Bull. Am. Mus. Nat. Hist. 1967; 138: 1-50Google Scholar, 8Gabe M. Saint Girons H. Histological data on the salivary glands of the Lepidosauria.Mém. Mus. Natn. Hist. Nat. Paris. 1969; 58: 1-112Google Scholar, 9Kochva E. Oral glands of the Reptilia.in: Gans C. Gans K.A. Biology of the Reptilia. 8. Academic Press, New York1978: 43-161Google Scholar) and dentition of snakes (10Young B. Kardong K. Dentitional surface features in snakes (Reptilia: Serpentes).Amphib.-Reptilia. 1996; 17: 261-276Crossref Scopus (44) Google Scholar). The fang may or may not be enlarged and can range from a solid tooth with or without grooving to an enclosed canaliculate channel as present in elapids and viperids (10Young B. Kardong K. Dentitional surface features in snakes (Reptilia: Serpentes).Amphib.-Reptilia. 1996; 17: 261-276Crossref Scopus (44) Google Scholar). Few comparative studies of the caenophidian venom system have been performed, although West (11West G.S. On the buccal glands and teeth of certain poisonous snakes.Proc. Zool. Soc. Lond. 1895; 1895: 195-206Google Scholar, 12West G. On the history of the salivary buccal and harderian glands of the colubroidae with notes on their tooth succession and the relationships of the poison ducts.J. Linn. Soc. Lond. Zool. 1898; 26: 517-526Crossref Scopus (4) Google Scholar) and Sarkar (13Sarkar S.C. A comparative study of the buccal glands and teeth of the opisthoglypha, and a discussion on the evolution of the order from aglypha.Proc. Zool. Soc. Lond. 1923; 1923: 295-322Google Scholar) described several different structural and topological features. A distinction was attempted between the venom glands of the front-fanged and non-front-fanged snakes with the glands in most non-front-fanged snakes termed “Duvernoy's glands” (7Taub A.M. Comparative histological studies on Duvernoy's gland of colubrid snakes.Bull. Am. Mus. Nat. Hist. 1967; 138: 1-50Google Scholar). Similarly, very little has been revealed about the composition of venoms from advanced snake lineages other than the three clades with high pressure, hollow front-fang venom delivery systems (Atractaspis, elapids, and viperids). Despite accounting for the majority of the families (Fig. 1 and Ref. 6Vidal N. Delmas A.S. David P. Cruaud C. Couloux A. Hedges S.B. The phylogeny and classification of caenophidian snakes inferred from seven nuclear protein-coding genes.C. R. Biol. 2007; 330: 182-187Crossref PubMed Scopus (172) Google Scholar) and ∼1900 of the 2500 advanced snake species, the multiple non-front-fanged families have received scant attention. Only a few studies have been undertaken, and even fewer have sequenced or bioactivity-tested individual toxins (2Fry B.G. Lumsden N. Wüster W. Wickramaratna J. Hodgson W.C. Kini R.M. Isolation of a neurotoxin (α-colubritoxin) from a ‘non-venomous’ colubrid: evidence for early origin of venom in snakes.J. Mol. Evol. 2003; 57: 446-452Crossref PubMed Scopus (125) Google Scholar, 14Fry B.G. Wüster W. Ramjan S.F.R. Jackson T. Martelli P. Kini R.M. LC/MS (liquid chromatography, mass spectrometry) analysis of Colubroidea snake venoms: evolutionary and toxinological implications.Rapid Commun. Mass Spectrom. 2003; 17: 2047-2062Crossref PubMed Scopus (137) Google Scholar, 15Huang P. Mackessy S.P. Biochemical characterization of phospholipase A2 (trimorphin) from the venom of the Sonoran Lyre Snake Trimorphodon biscutatus lambda (family Colubridae).Toxicon. 2004; 44: 27-36Crossref PubMed Scopus (31) Google Scholar, 16Lumsden N.G. Fry B.G. Ventura S. Kini R.M. Hodgson W.C. Pharmacological characterisation of a neurotoxin from the venom of Boiga dendrophila (Mangrove snake).Toxicon. 2005; 45: 329-334Crossref PubMed Scopus (49) Google Scholar, 17Lumsden N.G. Banerjee Y. Kini R.M. Kuruppu S. Hodgson W.C. Isolation and characterization of rufoxin, a novel protein exhibiting neurotoxicity from venom of the psammophiine Rhamphiophis oxyrhynchus (Rufous beaded snake).Neuropharmacology. 2007; 52: 1065-1070Crossref PubMed Scopus (25) Google Scholar, 18Ching A.T. Rocha M.M. Paes Leme A.F. Pimenta D.C. de Fatima M. Furtado D. Serrano S.M.T. Ho P.L. Junqueira de Azevedo I.L.M. Some aspects of the venom proteome of the Colubridae snake Philodryas olfersii revealed from a Duvernoy's (venom) gland transcriptome.FEBS Lett. 2006; 580 (Correction (2006) FEBS Lett. 580, 5122–5123): 4417-4422Crossref PubMed Scopus (92) Google Scholar). Studies of the first full-length toxins from non-front-fanged snakes were revealing, particularly the isolation and characterization of a potently neurotoxic three-finger toxin (3FTx) 1The abbreviations used are: 3FTx, three-finger toxin; CRISP, cysteine-rich secretory protein; SVMP, snake venom metalloprotease; ADAM, a disintegrin and metalloprotease; BLAST, Basic Local Alignment Search Tool; 3D, three-dimensional; SPDBV, Swiss-PdbViewer; MRI, magnetic resonance imaging; T, tesla; CVF, cobra venom factor; MMP, matrix metalloprotease; PLA2, phospholipase A2; CRD, cysteine-rich domain. from the colubrid snake Coelognathus radiatus (2Fry B.G. Lumsden N. Wüster W. Wickramaratna J. Hodgson W.C. Kini R.M. Isolation of a neurotoxin (α-colubritoxin) from a ‘non-venomous’ colubrid: evidence for early origin of venom in snakes.J. Mol. Evol. 2003; 57: 446-452Crossref PubMed Scopus (125) Google Scholar). This toxin type had long been considered the hallmark of elapid venoms and had been the subject of intense study (19Fry B.G. Wüster W. Kini R.M. Brusic V. Khan A. Venkataraman D. Rooney A.P. Molecular evolution of elapid snake venom three finger toxins.J. Mol. Evol. 2003; 57: 110-129Crossref PubMed Scopus (275) Google Scholar). Follow-up molecular phylogenetic studies demonstrated the shared origin of 3FTx and other toxin types across the entire advanced snake radiation (3Fry B.G. Wüster W. Assembling an arsenal: origin and evolution of the snake venom proteome inferred from phylogenetic analysis of toxin sequences.Mol. Biol. Evol. 2004; 21: 870-883Crossref PubMed Scopus (190) Google Scholar). In view of the homology of the venom toxins and toxin-secreting glands of all advanced snakes, the fact that Duvernoy's glands represented a primitive condition and that the derived glands of the front-fanged snakes were independently evolved from these, the distinction between Duvernoy's glands and venom glands was revealed to be an artificial one that impeded the understanding of the evolution of the venom apparatus of snakes. For this reason, the term Duvernoy's gland was abandoned, and the term “venom gland” was used for the toxin-secreting oral glands of all snakes regardless of the degree of anatomical specialization in the venom delivery apparatus (14Fry B.G. Wüster W. Ramjan S.F.R. Jackson T. Martelli P. Kini R.M. LC/MS (liquid chromatography, mass spectrometry) analysis of Colubroidea snake venoms: evolutionary and toxinological implications.Rapid Commun. Mass Spectrom. 2003; 17: 2047-2062Crossref PubMed Scopus (137) Google Scholar). It has been shown previously that snake venoms evolve via a process by which a gene encoding for a normal body protein, typically one involved in key regulatory processes or bioactivity, is duplicated, and the copy is selectively expressed in the venom gland (20Fry B.G. From genome to ‘venome’: molecular origin and evolution of the snake venom proteome inferred from phylogenetic analysis of toxin sequences and related body proteins.Genome Res. 2005; 15: 403-420Crossref PubMed Scopus (355) Google Scholar). The newly created toxin type evolves via the birth-and-death model of protein evolution in which a toxin multigene family is created by further gene duplication events followed by the deletion of some copies and conversion of others to non-functional copies or pseudogenes (19Fry B.G. Wüster W. Kini R.M. Brusic V. Khan A. Venkataraman D. Rooney A.P. Molecular evolution of elapid snake venom three finger toxins.J. Mol. Evol. 2003; 57: 110-129Crossref PubMed Scopus (275) Google Scholar). In addition to gene duplication, mutation is an important process that generates a tremendous diversity of venom toxins within these multigene families. The newly created toxin multigene families preserve the molecular scaffold of the ancestral protein but modify key functional residues at the tips of loops to acquire a myriad of newly derived activities (19Fry B.G. Wüster W. Kini R.M. Brusic V. Khan A. Venkataraman D. Rooney A.P. Molecular evolution of elapid snake venom three finger toxins.J. Mol. Evol. 2003; 57: 110-129Crossref PubMed Scopus (275) Google Scholar, 20Fry B.G. From genome to ‘venome’: molecular origin and evolution of the snake venom proteome inferred from phylogenetic analysis of toxin sequences and related body proteins.Genome Res. 2005; 15: 403-420Crossref PubMed Scopus (355) Google Scholar). Other mutations can include the selective expression of a particular domain, such as the expression of the disintegrin domain from snake venom metalloprotease, ADAM-type (SVMP/ADAM) toxins in viperid venoms (21Nei M. Gu X. Sitnikova T. Evolution by the birth-and-death process in multigene families of the vertebrate immune system.Proc. Natl. Acad. Sci. U. S. A. 1997; 94: 7799-7806Crossref PubMed Scopus (601) Google Scholar). These toxins have an unusual combination of precise specificity and extreme potency, characteristics that make them particularly amenable for use as investigational ligands or as leads for drug design and development (22Harvey A.L. Bradley K.N. Cochran S.A. Rowan E.G. Pratt J.A. Quillfeldt J.A. Jerusalinsky D.A. What can toxins tell us for drug discovery?.Toxicon. 1998; 36: 1635-1640Crossref PubMed Scopus (69) Google Scholar, 23Menez A. Functional architectures of animal toxins: a clue to drug design?.Toxicon. 1998; 36: 1557-1572Crossref PubMed Scopus (162) Google Scholar, 24Cushman D.W. Ondetti M.A. Gordon E.M. Natarajan S. Karanewsky D.S. Krapcho J. Petrillo Jr., E.W. Rational design and biochemical utility of specific inhibitors of angiotensin-converting enzyme.J. Cardiovasc. Pharmacol. 1987; 10: S17-30Crossref PubMed Scopus (45) Google Scholar). In this study we used a multidisciplinary approach to (a) characterize the venom transcriptomes of representative caenophidian snakes, (b) determine the timing of toxin recruitment events and patterns of toxin diversification, and (c) characterize changes in the venom delivery architecture. From comparison with the more widely studied elapids and viperids, we determined whether there are significant structural or functional differences in the evolution of the venom system and their associated toxins in the poorly characterized non-front-fanged caenophidian snakes. A total of 107 species representing each of the major lineages of advanced snakes were included in the study and examined using one or more of the following techniques: clone sequencing of cDNA libraries, gross dissection and examination of dentition, histology of venom glands and ducts, and magnetic resonance imaging (see “Appendix I” for details). In most cases different individuals were used as a source of material for each of these analyses.Appendix ISpecies and mode examined Open table in a new tab RNA was isolated from venom glands of 13 species spanning the full taxonomical diversity (10 non-front-fanged snakes, one elapid, and two viperids; see “Appendix I”) using the Qiagen RNeasy Midi kit with subsequent selection of mRNAs using the Oligotex Midi kit. cDNA libraries were constructed using the Clontech Creator SMART cDNA Library Construction kit and transformed into One Shot Electrocompetent GeneHogs (Invitrogen) as described previously (4Fry B.G. Vidal N. Norman J.A. Vonk F.J. Scheib H. Ramjan R. Kuruppu S. Fung K. Hedges S.B. Richardson M.K. Hodgson W.C. Ignjatovic V. Summerhayes R. Kochva E. Early evolution of the venom system in lizards and snakes.Nature. 2006; 439: 509-632Crossref Scopus (448) Google Scholar). Isolation and sequencing of inserts was undertaken at the Australian Genome Research Facility using BDTv3.1 chemistry with electrophoretic separation on an AB330xl. Up to 384 colonies were sequenced per library, inserts were screened for vector sequences, and those parts were removed prior to analysis and identification. Toxin sequences were identified by homology of the translated cDNA sequences with previously characterized toxins using a BLAST search of the Swiss-Prot protein database (www.expasy.org/tools/blast/). 3D models for caenophidian toxins were generated based on the assumption that homologous proteins share similar 3D structures (25Chothia C. Lesk A.M. The relation between the divergence of sequence and structure in proteins.EMBO J. 1986; 5: 823-826Crossref PubMed Scopus (1989) Google Scholar). In other words, the three-dimensional structure of a target protein can be modeled if its sequence is homologous to at least one template protein whose 3D structure has been determined experimentally by applying either x-ray or NMR techniques (26Greer J. Comparative model-building of the mammalian serine proteases.J. Mol. Biol. 1981; 153: 1027-1042Crossref PubMed Scopus (260) Google Scholar). In this work aligning the protein sequences of target and template(s) was carried out in SPDBV (27Guex N. Peitsch M.C. SWISS-MODEL and the Swiss-PdbViewer: an environment for comparative protein modeling.Electrophoresis. 1997; 18: 2714-2723Crossref PubMed Scopus (9641) Google Scholar), and the initial alignments were refined manually. From these alignments 3D models were built directly in SPDBV applying the “Build Preliminary Model” option, which is disabled in the currently distributed public version of the software. Loops were built by scanning a database of known loop structures using the same software, and suitable specimens were selected after visual inspection. The enthalpy of the resulting models was minimized applying two times 200 steps of Steepest Descent minimization. Finally the quality of each model structure was assessed in iMolTalk (28Diemand A.V. Scheib H. iMolTalk: an interactive, internet-based protein structure analysis server.Nucleic Acids Res. 2004; 32: W512-W516Crossref PubMed Scopus (44) Google Scholar), and a Van der Waals surface was calculated in MolMol (29Koradi R. Billeter M. Wuthrich K. MOLMOL: a program for display and analysis of macromolecular structures.J. Mol. Graph. 1996; 14: 51-55Crossref PubMed Scopus (6498) Google Scholar). In MolMol electrostatic potentials were calculated applying the “simplecharge” command and mapped on the model structure surface. The families of venom proteins were analyzed by superimposing the structures in SPDBV (27Guex N. Peitsch M.C. SWISS-MODEL and the Swiss-PdbViewer: an environment for comparative protein modeling.Electrophoresis. 1997; 18: 2714-2723Crossref PubMed Scopus (9641) Google Scholar), and conserved and variable structural regions were identified. In the molecular modeling of representative proteins, blue surface areas indicate positive charges, red surface areas indicate negative charges, and model pairs show sides of the protein rotated by 180°. 2Homology model coordinates can be obtained from H. Scheib. E-mail: [email protected] Molecular phylogenetic analyses of toxin transcripts were conducted using the translated amino acid sequences. Comparative sequences from other venomous reptiles and outgroups were obtained through BLAST searching (www.expasy.org/tools/blast/) using representative toxin sequences. To minimize confusion, all sequences obtained in this study are referred to by their GenBank™ accession numbers (www.ncbi.nlm.nih.gov/sites/entrez?db=Nucleotide), and sequences from previous studies are referred to by their UniProt/Swiss-Prot accession numbers (www.expasy.org/cgi-bin/sprot-search-ful). Resultant sequence sets were aligned using the program ClustalX followed by visual inspection for errors. When presented as sequence alignments, the leader sequence is shown in lowercase, the prepro region is underlined, cysteines are highlighted in black, and functional residues are in bold. Datasets were analyzed using Bayesian inference implemented on MrBayes, version 3.0b4. The analysis was performed by running a minimum of 1 × 106 generations in four chains and saving every 100th tree. The log likelihood score of each saved tree was plotted against the number of generations to establish the point at which the log likelihood scores of the analysis reached their asymptote, and the posterior probabilities for clades were established by constructing a majority rule consensus tree for all trees generated after the completion of the burn-in phase. 3Sequence alignments can be obtained from B. G. Fry. E-mail: [email protected] Gross dissection was performed on freshly euthanized and formalin-fixed specimens to document the relative size and position of the venom gland and associated skeletal musculature. Features of the maxillary dentition were scored using data from a previous study (10Young B. Kardong K. Dentitional surface features in snakes (Reptilia: Serpentes).Amphib.-Reptilia. 1996; 17: 261-276Crossref Scopus (44) Google Scholar) in which five morphological states were defined: 1) smooth surface and no enclosed venom canal, 2) no enclosed venom canal and surface with shallow furrow, 3) deep groove running the majority of the length of the tooth, 4) deep groove present but restricted to less than half the length of the tooth, and 5) enclosed venom canal. Histological sections were prepared from the intact head and the excised venom delivery system. Whole heads were removed, and a cut was made to the underside to allow fast penetration of the fixative (10% neutral buffered formalin). After a minimum of 2 days excess tissue was removed, and specimens were immersed in Kristensen's decalcification solution and placed on a rotor for up to 3 weeks (depending on the size of the head). Before processing the heads were bisected longitudinally for cutting transversely, at 3 μm, in two separate blocks. The processing schedule was: 10% formalin, 2 h; absolute ethanol, 4 × 1 h; Histolene, 3 × 1 h; paraffin wax, 2 × 90 min. The sections were taken every 100 μm, and matching sections were stained with periodic acid-Schiff stain and Masson's trichrome stain. In other specimens, the venom gland, venom duct, and the adjacent bony and muscular tissue were excised and placed in decalcifying solution (Cal-Ex, Fisher) for 72–168 h. Each sample was dehydrated and cleared through a progressive ethanol series and Cyto-Sol (Fisher) prior to embedding in Paraplast (Fisher). Serial sections were cut at 10–12 μm. All species were sectioned in the frontal plane; when available, the contralateral venom delivery system was sectioned either parasagittally or transversely. Sections were stained using a variant of Van Gieson's stain, which provides clear distinction between connective tissue, muscle, and epithelium, or with hematoxylin and eosin. Magnetic resonance imaging (MRI) was used to examine the three-dimensional shape and internal anatomy of the venom glands. Formalin-ethanol-fixed heads were first submersed in Fomblin (Solvay Solexis) to prevent air artifacts. Depending on head size, imaging was performed on either 9.4-T (small/medium) or 17.6-T (large) vertical 89-mm-bore systems (Bruker BioSpin, Rheinstetten, Germany) with a Bruker Micro2.5 gradient system of 1 T/m and transmit/receive birdcage radiofrequency coil with diameter of 10–30 mm. Bruker ParaVision 3.0 software was used for image acquisition. Anatomical images were acquired using a 3D gradient echo sequence. The field of view and matrix were varied to fit the individual samples, resulting in voxel sizes between (40)3 mm3. Imaging parameters were: echo time = 8 ms; repetition time = 40 ms; flip angle, 20°; four to eight averages; total scan time between 3 and 9 h per sample, depending on size and resolution. Image segmentation of the glands was performed manually in Amira 4.1 (Mercury Computer Systems Inc.), and 3D surface renderings were generated for all species. Analysis of venom gland cDNA from non-front-fanged snake libraries revealed the presence of transcripts with homology to previously characterized venom toxins from front-fanged snakes and venomous lizards (helodermatids and varanids) (Tables I and II). Transcripts sequenced were 3FTx (Figs. 2 and 3), C3/cobra venom factor (CVF) (Fig. 4), cysteine-rich secretory protein (CRISP) (Figs. 5 and 6), hyaluronidase (Fig. 7), kallikrein (Figs. 8 and 9), kunitz (Figs. 10 and 11), lectin (Figs. 12 and 13), matrix metalloprotease (MMP) (Fig. 14), phospholipase A2 (PLA2) Type IB (Fig. 15), SVMP/ADAM (Figs. 16, 17, and 18), and waprin (Fig. 19). Transcripts of five of these toxin types were also recovered from the cDNA libraries of the representative elapid Oxyuranus microlepidotus (3FTx, CRISP, kunitz, and waprin) and the viperid Causus rhombeatus (kallikrein).Table IToxin types recovered from mRNA transcript sampling3FTxCRICVFFac XKaKuLecNGFPLA2 Type IAPLA2 Type IBSVMPWapColubridaeX D. typusXXX T. dharaXXXX T. jacksoniiXXXX T. biscutatusXXXDipsadidae L. poecilogyrusXXXXX P. olfersiiXXXXXXElapidae O. microlepidotusXXXXXXHomalopsidae E. polylepisXXXXNatricidae R. tigrinusXXPsammophiinae P. mossambicusXXPseudoxyrhophiinae L. madagascariensisXXXXXViperidae Azemiops feaeXX C. rhombeatusXXXXX Open table in a new tab Table IITranscripts from non-front-fanged snakes and previously characterized basal and derived bioactivities from elapid or viperid venoms (19Fry B.G. Wüster W. Kini R.M. Brusic V. Khan A. Venkataraman D. Rooney A.P. Molecular evolution of elapid snake venom three finger toxins.J. Mol. Evol. 2003; 57: 110-129Crossref PubMed Scopus (275) Google Scholar)Toxin typeBioactivities3FTxAncestral toxic activity of α-neurotoxicity, antagonistically binding to the nicotinic acetylcholine receptor; α-neurotoxicity greatly potentiated by the deletion of the second and third ancestral cysteines. Functional derivations include binding to the postsynaptic muscarinic acetylcholine receptors, presynaptic neurotoxic action upon the L-type calcium channels, cytotoxic interactions, acetylcholinesterase inhibition, and others.C3/CVFAncestral activity of unregulated activation of the complement cascade causing rapid and significant problems such as anaphylactic-type problems and/or tissue damage via hemolysis/cytolysis. Derived activities not currently documented.CRISPAncestral activity of paralysis of peripheral smooth muscle and induction of hypothermia due to the action upon voltage-gated Ca2+ channels and resultant blockage of K+-induced contraction. Derived activities include blockage of cyclic nucleotide-gated calcium channels.HyaluronidaseVenom spreading factor.KallikreinAncestral toxic activity of increase of vascular permeability and production of hypotension in addition to stimulation of inflammation. Derived activities affect the blood, particularly targeting fibrinogen.KunitzAncestral toxic activity of inhibition of circulating plasma serine proteases. Derivations include inhibition of plasmin an" @default.
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• W2132785801 date "2008-02-01" @default.
• W2132785801 modified "2023-10-16" @default.
• W2132785801 title "Evolution of an Arsenal" @default.
• W2132785801 cites W1508885706 @default.
• W2132785801 cites W1964355523 @default.
• W2132785801 cites W1966004850 @default.
• W2132785801 cites W1976267307 @default.
• W2132785801 cites W1980318789 @default.
• W2132785801 cites W1988810952 @default.
• W2132785801 cites W1994152729 @default.
• W2132785801 cites W1995812051 @default.
• W2132785801 cites W2000191660 @default.
• W2132785801 cites W2001198282 @default.
• W2132785801 cites W2002195659 @default.
• W2132785801 cites W2004430180 @default.
• W2132785801 cites W2006284876 @default.
• W2132785801 cites W2007413963 @default.
• W2132785801 cites W2015642465 @default.
• W2132785801 cites W2016381427 @default.
• W2132785801 cites W2017123290 @default.
• W2132785801 cites W2017957136 @default.
• W2132785801 cites W2023194635 @default.
• W2132785801 cites W2030116431 @default.
• W2132785801 cites W2031336837 @default.
• W2132785801 cites W2033227089 @default.
• W2132785801 cites W2037352895 @default.
• W2132785801 cites W2038113812 @default.
• W2132785801 cites W2043037439 @default.
• W2132785801 cites W2044145349 @default.
• W2132785801 cites W2048912867 @default.
• W2132785801 cites W2049245690 @default.
• W2132785801 cites W2056196504 @default.
• W2132785801 cites W2057022817 @default.
• W2132785801 cites W2057190562 @default.
• W2132785801 cites W2057679413 @default.
• W2132785801 cites W2059356194 @default.
• W2132785801 cites W2069203940 @default.
• W2132785801 cites W2069346564 @default.
• W2132785801 cites W2070450843 @default.
• W2132785801 cites W2071471652 @default.
• W2132785801 cites W2073555092 @default.
• W2132785801 cites W2090919316 @default.
• W2132785801 cites W2093902019 @default.
• W2132785801 cites W2097470069 @default.
• W2132785801 cites W2100767681 @default.
• W2132785801 cites W2115702194 @default.
• W2132785801 cites W2117673203 @default.
• W2132785801 cites W2121333769 @default.
• W2132785801 cites W2125409836 @default.
• W2132785801 cites W2134105736 @default.
• W2132785801 cites W2134752229 @default.
• W2132785801 cites W2139833199 @default.
• W2132785801 cites W2140718009 @default.
• W2132785801 cites W2146086769 @default.
• W2132785801 cites W2149900524 @default.
• W2132785801 cites W2159377535 @default.
• W2132785801 cites W2159509794 @default.
• W2132785801 cites W2161047587 @default.
• W2132785801 cites W2163255992 @default.
• W2132785801 cites W2166647530 @default.
• W2132785801 cites W2166658567 @default.
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