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In recent years, the Noble false widow spider Steatoda nobilis (Thorell, 1875) has expanded its range globally and may represent a potential threat to native ecosystems and public health. Increasing numbers in synanthropic habitats have led to more human encounters and envenomations. Steatoda nobilis bites were previously classed as medically significant with similarities to bites from true black widows of the genus Latrodectus but deemed milder in onset, with symptoms generally ranging from mild to moderate. In this manuscript we present 16 new cases of S. nobilis envenomations bringing the total number of confirmed cases reported in the literature to 24. We report new symptoms and provide discussion on the contributing factors to pathology following bites by S. nobilis. We report a range of pathologies including necrosis, Latrodectus-like envenomation symptoms that include debilitating pain, tremors, fatigue, nausea, hypotension, and vectored bacterial infections including cellulitis and dermatitis. Symptoms ranged from mild to severe, requiring hospitalisation in some cases.
John P. Dunbar; Aiste Vitkauskaite; Derek T. O’Keeffe; Antoine Fort; Ronan Sulpice; Michel M. Dugon. Bites by the noble false widow spider Steatoda nobilis can induce Latrodectus-like symptoms and vector-borne bacterial infections with implications for public health: a case series. Clinical Toxicology 2021, 1 -12.
AMA StyleJohn P. Dunbar, Aiste Vitkauskaite, Derek T. O’Keeffe, Antoine Fort, Ronan Sulpice, Michel M. Dugon. Bites by the noble false widow spider Steatoda nobilis can induce Latrodectus-like symptoms and vector-borne bacterial infections with implications for public health: a case series. Clinical Toxicology. 2021; ():1-12.
Chicago/Turabian StyleJohn P. Dunbar; Aiste Vitkauskaite; Derek T. O’Keeffe; Antoine Fort; Ronan Sulpice; Michel M. Dugon. 2021. "Bites by the noble false widow spider Steatoda nobilis can induce Latrodectus-like symptoms and vector-borne bacterial infections with implications for public health: a case series." Clinical Toxicology , no. : 1-12.
The noble false widow spider Steatoda nobilis originates from the Macaronesian archipelago and has expanded its range globally. Outside of its natural range, it may have a negative impact on native wildlife, and in temperate regions it lives in synanthropic environments where it frequently encounters humans, subsequently leading to envenomations. S. nobilis is the only medically significant spider in Ireland and the UK, and envenomations have resulted in local and systemic neurotoxic symptoms similar to true black widows (genus Latrodectus). S. nobilis is a sister group to Latrodectus which possesses the highly potent neurotoxins called α-latrotoxins that can induce neuromuscular paralysis and is responsible for human fatalities. However, and despite this close relationship, the venom composition of S. nobilis has never been investigated. In this context, a combination of transcriptomic and proteomic cutting-edge approaches has been used to deeply characterise S. nobilis venom. Mining of transcriptome data for the peptides identified by proteomics revealed 240 annotated sequences, of which 118 are related to toxins, 37 as enzymes, 43 as proteins involved in various biological functions, and 42 proteins without any identified function to date. Among the toxins, the most represented in numbers are α-latrotoxins (61), δ-latroinsectotoxins (44) and latrodectins (6), all of which were first characterised from black widow venoms. Transcriptomics alone provided a similar representation to proteomics, thus demonstrating that our approach is highly sensitive and accurate. More precisely, a relative quantification approach revealed that latrodectins are the most concentrated toxin (28%), followed by α-latrotoxins (11%), δ-latroinsectotoxins (11%) and α-latrocrustotoxins (11%). Approximately two-thirds of the venom is composed of Latrodectus-like toxins. Such toxins are highly potent towards the nervous system of vertebrates and likely responsible for the array of symptoms occurring after envenomation by black widows and false widows. Thus, caution should be taken in dismissing S. nobilis as harmless. This work paves the way towards a better understanding of the competitiveness of S. nobilis and its potential medical importance.
John P. Dunbar; Antoine Fort; Damien Redureau; Ronan Sulpice; Michel M. Dugon; Loïc Quinton. Venomics Approach Reveals a High Proportion of Lactrodectus-Like Toxins in the Venom of the Noble False Widow Spider Steatoda nobilis. Toxins 2020, 12, 402 .
AMA StyleJohn P. Dunbar, Antoine Fort, Damien Redureau, Ronan Sulpice, Michel M. Dugon, Loïc Quinton. Venomics Approach Reveals a High Proportion of Lactrodectus-Like Toxins in the Venom of the Noble False Widow Spider Steatoda nobilis. Toxins. 2020; 12 (6):402.
Chicago/Turabian StyleJohn P. Dunbar; Antoine Fort; Damien Redureau; Ronan Sulpice; Michel M. Dugon; Loïc Quinton. 2020. "Venomics Approach Reveals a High Proportion of Lactrodectus-Like Toxins in the Venom of the Noble False Widow Spider Steatoda nobilis." Toxins 12, no. 6: 402.
Venoms are best known for their ability to incapacitate prey. In predatory groups, venom potency is predicted to reflect ecological and evolutionary drivers relating to diet. While venoms have been found to have prey-specific potencies, the role of diet breadth on venom potencies has yet to be tested at large macroecological scales. Here, using a comparative analysis of 100 snake species, we show that the evolution of prey-specific venom potencies is contingent on the breadth of a species’ diet. We find that while snake venom is more potent when tested on species closely related to natural prey items, we only find this prey-specific pattern in species with taxonomically narrow diets. While we find that the taxonomic diversity of a snakes’ diet mediates the prey specificity of its venom, the species richness of its diet was not found to affect these prey-specific potency patterns. This indicates that the physiological diversity of a species’ diet is an important driver of the evolution of generalist venom potencies. These findings suggest that the venoms of species with taxonomically diverse diets may be better suited to incapacitating novel prey species and hence play an important role for species within changing environments.
Keith Lyons; Michel M. Dugon; Kevin Healy. Diet Breadth Mediates the Prey Specificity of Venom Potency in Snakes. Toxins 2020, 12, 74 .
AMA StyleKeith Lyons, Michel M. Dugon, Kevin Healy. Diet Breadth Mediates the Prey Specificity of Venom Potency in Snakes. Toxins. 2020; 12 (2):74.
Chicago/Turabian StyleKeith Lyons; Michel M. Dugon; Kevin Healy. 2020. "Diet Breadth Mediates the Prey Specificity of Venom Potency in Snakes." Toxins 12, no. 2: 74.
Introduction: Snakes, insects, arachnids and myriapods have been linked to necrosis following envenomation. However, the pathways involved in arthropod venom-induced necrosis remain a highly controversial topic among toxinologists, clinicians and the public. On the one hand, clinicians report on alleged envenomations based on symptoms and the victims’ information. On the other hand, toxinologists and zoologists argue that symptoms are incompatible with the known venom activity of target species. This review draws from the literature on arthropod envenomations, snakebite, and inflammatory processes to suggest that envenomation by a range of organisms might trigger an intense inflammatory cascade that ultimately lead to necrosis. If confirmed, these processes would have important implications for the treatment of venom-induced necrosis. Objectives: To describe two inflammatory pathways of regulated necrosis, tumour necrosis factor (necroptosis) and Neutrophil Extracellular Traps (NETosis); to discuss existing knowledge about snake venom and arachnid-induced necrosis demonstrating the involvement of tumour necrosis factor and neutrophils in the development of tissue necrosis following envenomation and to contribute to the understanding of venom-induced necrosis by arthropods and provide clinicians with an insight into little known inflammatory processes which may occur post envenomation. Methods: ISI Web of Science databases were searched using the terms “spider bite necrosis”, “arthropod envenomation necrosis”, “venom necrosis”, “venom immune response”, “loxoscelism”, “arachnidism”, “necroptosis venom”, “necroptosis dermatitis”, “tumour necrosis factor TNF venom”, “scorpionism”, “scolopendrism”, “centipede necrosis”, “NETosis venom”, “NETosis necrosis”. Searches produced 1737 non-duplicate citations of which 74 were considered relevant to this manuscript. Non-peer-reviewed sources or absence of voucher material identifying the organism were excluded. What is necrosis? Necrosis is the breakdown of cell membrane integrity followed by inflowing extracellular fluid, organelle swelling and the release of proteolytic enzymes into the cytosol. Necrosis was historically considered an unregulated process; however, recent studies demonstrate that necrosis can also be a programmed event resulting from a controlled immune response (necroptosis). Tumour necrosis factor and the necroptosis pathway: Tumour necrosis factor is a pro-inflammatory cytokine involved in regulating immune response, inflammation and cell death/survival. The pro-inflammatory cytokine TNF-α participates in the development of necrosis after envenomation by vipers. Treatment with TNF-α-antibodies may significantly reduce the manifestation of necrosis. Neutrophil Extracellular Traps and the NETosis pathway: The process by which neutrophils discharge a mesh of DNA strands in the extracellular matrix to entangle (“trap”) pathogens, preventing them from disseminating. Neutrophil Extracellular Traps have been recently described as important in venom-induced necrosis. Trapped venom accumulates at the bite site, resulting in significant localized necrosis. Arthropod venom driving necrosis: Insects, myriapods and arachnids can induce necrosis following envenomation. So far, the processes involved have only been investigated in two arachnids: Loxosceles spp. (recluse spiders) and Hemiscorpius lepturus (scorpion). Loxosceles venom contains phospholipases D which hydrolyse sphingomyelin, resulting in lysis of muscle fibers. Subsequently liberated ceramides act as intermediaries that regulate TNF-α and recruit neutrophils. Experiments show that immune-deficient mice injected with Loxosceles venom experience less venom-induced inflammatory response and survive longer than control mice. Necrosis following Hemiscorpius lepturus stings correlates with elevated concentrations of TNF-α. These observations suggest that necrosis may be indirectly triggered or worsened by pathways of regulated necrosis in addition to necrotic venom compounds. Conclusions: Envenomation often induce an intense inflammatory cascade, which under certain circumstances may produce necrotic lesions independently from direct venom activity. This could explain the inconsistent and circumstantial occurrence of necrosis following envenomation by a range of organisms. Future research should focus on identifying pathways to regulated necrosis following envenomation and determining more efficient ways to manage inflammation. We suggest that clinicians should consider the victim’s immune response as an integral part of the envenomation syndrome.
John P. Dunbar; Ronan Sulpice; Michel M. Dugon. The kiss of (cell) death: can venom-induced immune response contribute to dermal necrosis following arthropod envenomations? Clinical Toxicology 2019, 57, 677 -685.
AMA StyleJohn P. Dunbar, Ronan Sulpice, Michel M. Dugon. The kiss of (cell) death: can venom-induced immune response contribute to dermal necrosis following arthropod envenomations? Clinical Toxicology. 2019; 57 (8):677-685.
Chicago/Turabian StyleJohn P. Dunbar; Ronan Sulpice; Michel M. Dugon. 2019. "The kiss of (cell) death: can venom-induced immune response contribute to dermal necrosis following arthropod envenomations?" Clinical Toxicology 57, no. 8: 677-685.
John P. Dunbar; Collie Ennis; Robert Gandola; Michel M. Dugon. Biting off more than one can chew: first record of the non-native Noble false widow spider Steatoda nobilis (Thorell, 1875) feeding on the native Viviparous lizard Zootoca vivipara (Lichtenstein, 1823) in Ireland. Biology & Environment: Proceedings of the Royal Irish Academy 2018, 118B, 45 .
AMA StyleJohn P. Dunbar, Collie Ennis, Robert Gandola, Michel M. Dugon. Biting off more than one can chew: first record of the non-native Noble false widow spider Steatoda nobilis (Thorell, 1875) feeding on the native Viviparous lizard Zootoca vivipara (Lichtenstein, 1823) in Ireland. Biology & Environment: Proceedings of the Royal Irish Academy. 2018; 118B (1):45.
Chicago/Turabian StyleJohn P. Dunbar; Collie Ennis; Robert Gandola; Michel M. Dugon. 2018. "Biting off more than one can chew: first record of the non-native Noble false widow spider Steatoda nobilis (Thorell, 1875) feeding on the native Viviparous lizard Zootoca vivipara (Lichtenstein, 1823) in Ireland." Biology & Environment: Proceedings of the Royal Irish Academy 118B, no. 1: 45.
Objective: The noble false widow Steatoda nobilis is the only medically significant spider known to occur in the British Isles and Ireland, with a single case of steatodism ever reported from Great Britain. We present here five new cases of envenomations by S. nobilis, three from Ireland and two from Great Britain and describe symptoms not previously reported for the genus Steatoda. Case presentation: Four adult males and one adult female with confirmed S. nobilis bites reported their symptoms to the authors. General practitioner chart was obtained for case #3. In all five cases, envenomations were immediately followed by a sharp and prolonged onset of pain, mild to extensive erythema and localised to extensive swelling around the bite site. Additional symptoms include moderate to intense pruritus, vasodilation of the capillaries around the bite site and a possible minor necrotic wound. Conclusion: In all cases, symptoms subsided within 48–72 h and no further complications were reported. Envenomations by S. nobilis seem to produce symptoms similar (but not identical) to those previously reported from other Steatoda sp. Considering their benign outcome, envenomations by S. nobilis should still be regarded as of moderate medical importance, requiring monitoring and pain management strategies.
John P. Dunbar; Sam Afoullouss; Ronan Sulpice; Michel Dugon. Envenomation by the noble false widow spider Steatoda nobilis (Thorell, 1875) – five new cases of steatodism from Ireland and Great Britain. Clinical Toxicology 2017, 56, 433 -435.
AMA StyleJohn P. Dunbar, Sam Afoullouss, Ronan Sulpice, Michel Dugon. Envenomation by the noble false widow spider Steatoda nobilis (Thorell, 1875) – five new cases of steatodism from Ireland and Great Britain. Clinical Toxicology. 2017; 56 (6):433-435.
Chicago/Turabian StyleJohn P. Dunbar; Sam Afoullouss; Ronan Sulpice; Michel Dugon. 2017. "Envenomation by the noble false widow spider Steatoda nobilis (Thorell, 1875) – five new cases of steatodism from Ireland and Great Britain." Clinical Toxicology 56, no. 6: 433-435.
With approximately 3,500 species distributed across five extant orders, centipedes (class Chilopoda) make the second most speciose class among the subphylum Myriapoda. The most conspicuous synapomorphic character of centipedes is certainly the modification of the first pair of legs into powerful venomous forceps (the forcipules). The venom gland encased in each forcipule produces a potent cocktail of paralytic toxins delivered into prey and opponents via a cuticular duct which opens on the subterminal part of the apical claw. It has been hypothesized that this modification, unique in the animal world, results from the folding of the outer cuticle of the walking legs and the transformation of related subepidermal gland units into venom-producing cells as an adaptation to a new terrestrial predatory niche over 430 million years ago, thus making centipedes one of the most ancient known clade of terrestrial venomous organisms. However, despite their global distribution, synanthropic habits, and reputation for inflicting painful stings, little is known about centipedes and their venom system. This chapter reviews the current knowledge on the development, the evolutionary trajectory, the anatomy, the physiology, and the predatory ecology of centipedes, with a strong emphasis on the forcipular apparatus.
Michel M. Dugon. Evolution, Morphology, and Development of the Centipede Venom System. Toxins and Drug Discovery 2017, 261 -278.
AMA StyleMichel M. Dugon. Evolution, Morphology, and Development of the Centipede Venom System. Toxins and Drug Discovery. 2017; ():261-278.
Chicago/Turabian StyleMichel M. Dugon. 2017. "Evolution, Morphology, and Development of the Centipede Venom System." Toxins and Drug Discovery , no. : 261-278.
Michel M. Dugon; John P. Dunbar; Sam Afoullouss; Janic Schulte; Amanda McEvoy; Michael J. English; Ruth Hogan; Collie EnnisRonan Sulpice. Occurrence, reproductive rate and identification of the non-native Noble false widow spider Steatoda nobilis (Thorell, 1875) in Ireland. Biology & Environment: Proceedings of the Royal Irish Academy 2017, 117, 77 .
AMA StyleMichel M. Dugon, John P. Dunbar, Sam Afoullouss, Janic Schulte, Amanda McEvoy, Michael J. English, Ruth Hogan, Collie EnnisRonan Sulpice. Occurrence, reproductive rate and identification of the non-native Noble false widow spider Steatoda nobilis (Thorell, 1875) in Ireland. Biology & Environment: Proceedings of the Royal Irish Academy. 2017; 117 (2):77.
Chicago/Turabian StyleMichel M. Dugon; John P. Dunbar; Sam Afoullouss; Janic Schulte; Amanda McEvoy; Michael J. English; Ruth Hogan; Collie EnnisRonan Sulpice. 2017. "Occurrence, reproductive rate and identification of the non-native Noble false widow spider Steatoda nobilis (Thorell, 1875) in Ireland." Biology & Environment: Proceedings of the Royal Irish Academy 117, no. 2: 77.
The requirement for high quality/non-degraded RNA is essential for an array of molecular biology analyses. When analysing the integrity of rRNA from the barnacleLepas anatifera(Phylum Arthropoda, Subphylum Crustacea), atypical or sub-optimal rRNA profiles that were apparently degraded were observed on a bioanalyser electropherogram. It was subsequently discovered that the rRNA was not degraded, but arose due to a ‘gap deletion’ (also referred to as ‘hidden break’) in the 28S rRNA. An apparent excision at this site caused the 28S rRNA to fragment under heat-denaturing conditions and migrate along with the 18S rRNA, superficially presenting a ‘degraded’ appearance. Examination of the literature showed similar observations in a small number of older studies in insects; however, reading across multiple disciplines suggests that this is a wider issue that occurs across the Animalia and beyond. The current study shows that the 28S rRNA anomaly goes far beyond insects within the Arthropoda and is widespread within this phylum. We confirm that the anomaly is associated with thermal conversion because gap-deletion patterns were observed in heat-denatured samples but not in gels with formaldehyde-denaturing.
Sean D. McCarthy; Michel Dugon; Anne Marie Power. ‘Degraded’ RNA profiles in Arthropoda and beyond. PeerJ 2015, 3, e1436 .
AMA StyleSean D. McCarthy, Michel Dugon, Anne Marie Power. ‘Degraded’ RNA profiles in Arthropoda and beyond. PeerJ. 2015; 3 ():e1436.
Chicago/Turabian StyleSean D. McCarthy; Michel Dugon; Anne Marie Power. 2015. "‘Degraded’ RNA profiles in Arthropoda and beyond." PeerJ 3, no. : e1436.
With approximately 3,500 species distributed across five extant orders, centipedes (class Chilopoda) make the second most speciose class among the subphylum Myriapoda. The most conspicuous synapomorphic character of centipedes is certainly the modification of the first pair of legs into powerful venomous forceps (the forcipules). The venom gland encased in each forcipule produces a potent cocktail of paralytic toxins delivered into prey and opponents via a cuticular duct which opens on the subterminal part of the apical claw. It has been hypothesized that this modification, unique in the animal world, results from the folding of the outer cuticle of the walking legs and the transformation of related subepidermal gland units into venom-producing cells as an adaptation to a new terrestrial predatory niche over 430 million years ago, thus making centipedes one of the most ancient known clade of terrestrial venomous organisms. However, despite their global distribution, synanthropic habits, and reputation for inflicting painful stings, little is known about centipedes and their venom system. This chapter reviews the current knowledge on the development, the evolutionary trajectory, the anatomy, the physiology, and the predatory ecology of centipedes, with a strong emphasis on the forcipular apparatus.
Michel M. Dugon. Evolution, Morphology and Development of the Centipede Venom System. Toxins and Drug Discovery 2015, 1 -15.
AMA StyleMichel M. Dugon. Evolution, Morphology and Development of the Centipede Venom System. Toxins and Drug Discovery. 2015; ():1-15.
Chicago/Turabian StyleMichel M. Dugon. 2015. "Evolution, Morphology and Development of the Centipede Venom System." Toxins and Drug Discovery , no. : 1-15.
In contrast to previous claims that (a) there is a law of recapitulation and, conversely, (b) recapitulation never happens, the evolutionary repatterning of development can take many forms, of which recapitulation is one. Here, we add another example to the list of case studies of recapitulation. This example involves the development of the venom claws (forcipules) in the centipede Scolopendra subspinipes mutilans, and in particular the development of the duct through which venom flows from the gland that produces it (proximal) to the opening called the meatus (distal) through which it is injected into prey. Most of the information we present is from early postembryonic stages--these have been neglected in previous work on centipede development. We show that the venom ducts arise from sutures that are invaginations of the cuticle. In S. s. mutilans, the invagination in each forcipule forms into a tubular structure that detaches itself from the exoskeleton and moves toward the center of the forcipule. This is in contrast to extant Scutigera, and also, probably, Scolopendra's extinct Scutigera-like ancestors, where the duct remains attached to the cuticle of throughout development. Thus, S. s. mutilans exhibits a recapitulatory repatterning of development.
Michel M. Dugon; Luke Hayden; Alexander Black; Wallace Arthur. Development of the venom ducts in the centipedeScolopendra: an example of recapitulation. Evolution & Development 2012, 14, 515 -521.
AMA StyleMichel M. Dugon, Luke Hayden, Alexander Black, Wallace Arthur. Development of the venom ducts in the centipedeScolopendra: an example of recapitulation. Evolution & Development. 2012; 14 (6):515-521.
Chicago/Turabian StyleMichel M. Dugon; Luke Hayden; Alexander Black; Wallace Arthur. 2012. "Development of the venom ducts in the centipedeScolopendra: an example of recapitulation." Evolution & Development 14, no. 6: 515-521.
Many animal phyla contain clades in which most or all species are venom-injecting predators. An example, in the arthropods, is the class Chilopoda, containing the approximately 3500 species of centipedes. Very little ecological or behavioural work yielding quantitative data has been conducted on centipede predation. Here, we describe a study of this kind. Our experiments employed one centipede species - a large tropical one, Scolopendra subspinipes mutilans - and two species of prey - a cricket, Gryllus assimilis, and a locust, Schistocerca gregaria. We conducted two experiments. The first was aimed at investigating the extent to which the centipedes attacked prey in particular tagmata as opposed to at random over the whole body surface. The results showed that the centipedes were highly selective, preferring to attack the head or thorax rather than the abdomen; indeed, they often reoriented the prey in order to achieve this. A possible explanation of this behaviour is to maximize the speed with which the neurotoxins in the venom reach either the brain or the thoracic ganglia that control limb movement. The second experiment was aimed at investigating the effect of venom-extraction on the attack rate, and specifically at testing if the magnitude of any such effect differed between the two types of prey, which differ considerably in size. The results showed a major effect of venom extraction in relation to both types of prey, but with the time taken to return to a 'normal' attack rate being longer in the case of the larger prey-type, namely the locust. We discuss these results in relation to the 'venom optimization hypothesis' and, more generally, to the principle of minimizing the production/use of venom, which is an energetically expensive resource.
Michel M. Dugon; Wallace Arthur. Prey orientation and the role of venom availability in the predatory behaviour of the centipede Scolopendra subspinipes mutilans (Arthropoda: Chilopoda). Journal of Insect Physiology 2012, 58, 874 -880.
AMA StyleMichel M. Dugon, Wallace Arthur. Prey orientation and the role of venom availability in the predatory behaviour of the centipede Scolopendra subspinipes mutilans (Arthropoda: Chilopoda). Journal of Insect Physiology. 2012; 58 (6):874-880.
Chicago/Turabian StyleMichel M. Dugon; Wallace Arthur. 2012. "Prey orientation and the role of venom availability in the predatory behaviour of the centipede Scolopendra subspinipes mutilans (Arthropoda: Chilopoda)." Journal of Insect Physiology 58, no. 6: 874-880.
The forcipules of centipedes are the only known example in the animal kingdom of an evolutionary transition from walking legs to venom-injecting appendages. They provide a classic case of an evolutionary novelty under most (but not all) definitions of that concept. Although there is a reasonable literature on forcipules, and on the forcipular segment more generally, it is fragmentary and scattered. Also, many previous studies have been based on a single species and hence have no comparative component. Here, we build on this earlier literature by providing detailed qualitative and quantitative information on the forcipular segments of representatives of the five extant orders of centipedes. Our results reveal notable differences between the orders - as well as considerable variation within some of them. The pattern of inter-group differences can be used to infer, albeit cautiously, a major evolutionary trend from a presumed scutigeromorph-like last common ancestor (LCA), in which the forcipules were probably leg-like (as in present-day scutigeromorphs) to a more specialized claw-like structure with movement restricted to the horizontal plane. This morphological trend may reflect an ecological trend from open-habitat ambush predation to leaf-litter and subterranean predatory opportunism.
Michel M. Dugon; Alexander Black; Wallace Arthur. Variation and specialisation of the forcipular apparatus of centipedes (Arthropoda: Chilopoda): A comparative morphometric and microscopic investigation of an evolutionary novelty. Arthropod Structure & Development 2012, 41, 231 -243.
AMA StyleMichel M. Dugon, Alexander Black, Wallace Arthur. Variation and specialisation of the forcipular apparatus of centipedes (Arthropoda: Chilopoda): A comparative morphometric and microscopic investigation of an evolutionary novelty. Arthropod Structure & Development. 2012; 41 (3):231-243.
Chicago/Turabian StyleMichel M. Dugon; Alexander Black; Wallace Arthur. 2012. "Variation and specialisation of the forcipular apparatus of centipedes (Arthropoda: Chilopoda): A comparative morphometric and microscopic investigation of an evolutionary novelty." Arthropod Structure & Development 41, no. 3: 231-243.
The venom-injecting forcipules of centipedes represent an evolutionary novelty that appeared in the centipede stem lineage more than 400 Ma. No other lineage of arthropods (or indeed of animals) has evolved claws for injecting venom from a pair of walking legs. However, little is known of the development, ultrastructure, or detailed function of centipede forcipules. Here, we provide comparative structural information on the venom duct apparatus that is the main functional system within each forcipule, based on scanning electron microscopy and transmission electron microscopy studies. We also give comparative developmental information, using DAPI staining, on embryonic forcipules from the four main centipede orders, including Scutigeromorpha. The photographs of Scutigera embryos we present are the first to be published for any species belonging to this order. The structure of the venom apparatus within each forcipule represents a discrete element of the novelty, whose origin requires a special explanation. This is in contrast to the novel external shape of the forcipules, which can be arrived at gradually by a series of changes from the starting point of a standard walking leg. Drawing on a proposed structural homology between venom glands and epidermal glands, we present a hypothesis of how the venom gland and duct may have arisen in evolution.
Michel M. Dugon; Wallace Arthur. Comparative studies on the structure and development of the venom-delivery system of centipedes, and a hypothesis on the origin of this evolutionary novelty. Evolution & Development 2012, 14, 128 -137.
AMA StyleMichel M. Dugon, Wallace Arthur. Comparative studies on the structure and development of the venom-delivery system of centipedes, and a hypothesis on the origin of this evolutionary novelty. Evolution & Development. 2012; 14 (1):128-137.
Chicago/Turabian StyleMichel M. Dugon; Wallace Arthur. 2012. "Comparative studies on the structure and development of the venom-delivery system of centipedes, and a hypothesis on the origin of this evolutionary novelty." Evolution & Development 14, no. 1: 128-137.