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1.
Avian Dis ; 63(4): 551-558, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31865668

RESUMO

This study provides a detailed description of the major morphoanatomic and ultrastructural features of the nasal gland in turkeys. In this avian species, nasal or salt glands are bilateral, pale pink, elongated to spindle-shaped, serous, tubuloalveolar structures, with a mean length ranging from 0.64 ± 0.15 cm in poults of 4 days of age to 2.15 ± 0.17 cm at 22 weeks. Instead of having a supraorbital location as commonly seen in waterfowl and other avian species, these glands run underneath the lacrimal, frontal, and nasal bones in turkeys. The reference point for sample collection for histologic examination is just before the rostral edge of the eyelid. Each gland adheres to the surrounding bone through a thick capsule of dense connective tissue merging with the skull periosteum. Histologically, the salt gland consists of secretory tubuloalveolar structures, lined by cuboidal epithelial cells with a central canaliculus and ducts. There are small and large ducts lined by a bilayered epithelium consisting of large apical columnar secretory cells occasionally admixed with rare cuboidal cells. These cells are periodic acid Schiff negative and slightly Alcian blue positive. Both alveolar and secretory ductal cells contain slightly electrondense granular vesicles, highly folded lateral surfaces, and large numbers of mitochondria, characteristic of ion-transporting epithelia. This study provides valuable information for the accurate identification and localization of the nasal gland during necropsy, as well as its correct histologic interpretation, ultimately improving our understanding of the role of this gland in the pathophysiology of specific diseases in turkeys.


Assuntos
Glândulas Exócrinas/anatomia & histologia , Glândula de Sal/anatomia & histologia , Perus/anatomia & histologia , Animais , Glândulas Exócrinas/ultraestrutura , Feminino , Masculino , Nariz/anatomia & histologia , Nariz/ultraestrutura , Glândula de Sal/ultraestrutura
2.
Toxicon ; 164: 71-81, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30998944

RESUMO

Most colubrid snake venoms have been poorly studied, despite the fact that they represent a great resource for biological, ecological, toxinological and pharmacological research. Herein, we explore the venom delivery system of the Aesculapian False Coral Snake Erythrolamprus aesculapii as well as some biochemical and toxicological properties of its venom. Its Duvernoy's venom gland is composed of serous secretory cells arranged in densely packed secretory tubules, and the most striking feature of its fang is their double-curved shape, exhibiting a beveled bladelike appearance near the tips. Although E. aesculapii resembles elapid snakes of the genus Micrurus in color pattern, this species produces a venom reminiscent of viperid venoms, containing mainly tissue-damaging toxins such as proteinases. Prominent hemorrhage developed both locally and systemically in mice injected with the venom, and the minimum hemorrhagic dose was found to be 18.8 µg/mouse; the lethal dose, determined in mice, was 9.5 ±â€¯3.7 µg/g body weight. This work has toxicological implications that bites to humans by E. aesculapii could result in moderately severe local (and perhaps systemic) hemorrhage and gives insight into future directions for research on the venom of this species.


Assuntos
Colubridae/anatomia & histologia , Venenos de Serpentes/química , Venenos de Serpentes/toxicidade , Animais , Antivenenos/imunologia , Glândulas Exócrinas/anatomia & histologia , Feminino , Hemorragia/induzido quimicamente , Humanos , Masculino , Maxila/ultraestrutura , Camundongos , Microscopia Eletrônica de Varredura , Proteólise , Mordeduras de Serpentes , Venenos de Serpentes/imunologia , Dente/ultraestrutura
3.
Arthropod Struct Dev ; 50: 24-42, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30894327

RESUMO

Bombardier beetles are famous for their unique ability to explosively discharge hot quinones from their pygidial glands when threatened. Here we provide the first detailed description of the ultrastructure of the defensive gland system of the genus Paussus, the most speciose genus in the ground beetle subfamily Paussinae. Paussine beetles are commonly known as "flanged bombardier beetles" due to the presence of a flange on their elytra that assists in directing their defensive chemicals toward the front of their bodies. In this paper, we use optical, fluorescence and focused ion beam (FIB/SEM) microscopy to analyse and illustrate anatomy and ultrastructure of the explosive defensive system of Paussus favieri, a charismatic myrmecophilous species. The defensive system of this species consists of two independent, symmetrical glands each composed of secretory lobes, a long collecting duct, a bilobed reservoir chamber, a cuticular valve, a sclerotized reaction chamber, and an accessory chamber, associated with the reaction chamber, that is surrounded by several isolated glandular cells. Differences between the pygidial defensive systems of Paussus favieri and those of Brachininae are discussed.


Assuntos
Besouros/anatomia & histologia , Animais , Formigas , Besouros/ultraestrutura , Glândulas Exócrinas/anatomia & histologia , Glândulas Exócrinas/ultraestrutura , Feminino , Cadeia Alimentar , Masculino , Microscopia Eletrônica de Varredura , Microscopia de Fluorescência
4.
Arthropod Struct Dev ; 49: 19-25, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30703537

RESUMO

The pygidial gland system is a key innovation in adephagan beetles, producing, storing, and spraying defensive chemical compounds. As the source of defensive chemical production and storage, the pygidial gland system experiences severe chemical stress which challenges the integrity of the entire gland system. Here, we utilize autofluorescence-based confocal laser scanning microscopy to examine the morphology of pygidial gland secretory lobes and collecting ductules in a common Pennsylvanian harpaline species, Harpalus pensylvanicus. The glandular units are composed of type-III exocrine cells which empty into resilin-rich ductules, which themselves lead into a larger resilin-rich collecting duct, and ultimately the pygidial reservoir pump. We also utilize histological staining with toluidine blue and brightfield imaging to provide additional support for the presence of resilin in the collecting duct, as toluidine blue has been shown to stain resilin without metachromasia. We hypothesize that the high resilin content of the collecting ducts might be a widespread key evolutionary adaptation to prevent damage caused by physical and chemical stress generated in pump-containing insect exocrine gland systems.


Assuntos
Besouros/anatomia & histologia , Proteínas de Insetos/análise , Animais , Glândulas Exócrinas/anatomia & histologia , Microscopia Confocal
5.
Arthropod Struct Dev ; 49: 85-102, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30496890

RESUMO

This study is the first attempt to describe the ultrastructure and functional morphology of the dermal glands in Limnochares aquatica (L., 1758). The dermal glands were studied using light-optical, SEM and TEM microscopy methods during different stages of their activity. In contrast to the vast majority of other fresh water mites, dermal glands of the studied species are originally multiplied and scattered freely over the mite body surface. The opening of the glands is saddle-like, formed of several tight cuticular folds and oriented freely to the long axis of the mite body. Either a small cuticular spine or, rarely, a slim sensitive seta is placed on one pole of the opening. On the inside, the central gland portion is provided with a complex cuticular helicoid armature. The glands are composed of prismatic cells situated around the intra-alveolar lumen, variously present, and look like a fig-fruit with the basal surface facing the body cavity. The glands are provided with extremely numerous microtubules, frequently arranged in bundles, and totally devoid of synthetic apparatus such as RER cisterns and Golgi bodies. Three states of the gland morphology depending on their functional activity may be recognized: (i) glands without secretion with highly folded cell walls and numerous microtubules within the cytoplasm, (ii) glands with an electron-dense granular secretion in the expanded vacuoles and (iii) glands with the secretion totally extruded presenting giant empty vacuoles bordered with slim cytoplasmic strips on the periphery. Summer specimens usually show the first gland state, whereas winter specimens, conversely, more often demonstrate the second and the third states. This situation may depend on some factors like changes of the seasonal temperature, pH, or oxygenation of the ambient water. On the assumption of the morphological characters, dermal glands may be classified not as secretory but as a special additional excretory organ system of the body cavity. Despite the glands lack cambial cells, restoration of functions after releasing of 'secretion' looks possible. Organization of dermal glands is discussed in comparison to other water mites studied.


Assuntos
Ácaros/anatomia & histologia , Animais , Glândulas Exócrinas/anatomia & histologia , Glândulas Exócrinas/ultraestrutura , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Ácaros/ultraestrutura
6.
PLoS One ; 13(7): e0200309, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30044803

RESUMO

To become integrated into an ant society, myrmecophilous parasites must overcome both the defenses and the communication system of their hosts. Some aleocharine staphylinid beetles employ chemical and tactile strategies to invade colonies, where they later consume ant brood and participate in parasitic trophallaxis with host ants. By producing compounds that both appease their hosts and stimulate adoption, the beetles are able to live in and deposit their own eggs in the well defended ant nest. In the current paper, previous findings on the myrmecophilous behavior and morphological features of the staphylinid beetle Lomechusoides (formerly Lomechusa) strumosus are reviewed and re-evaluated. Hitherto unpublished results concerning the beetles' ability to participate in the social food flow of their host ants are reported. Furthermore, we present an analysis and documentation of the behavioral interactions between beetles and host ants during the adoption process, and we report new histological and scanning electron microscopic analyses of the exocrine glands and morphological adaptations that underlie the myrmecophilous behavior of L. strumosus. The main features of L. strumosus are compared with those of the staphilinid myrmecophile Lomechusa (formerly Atemeles) pubicollis. The paper concludes with a description of the life trajectory of L. strumosus and presents a brief history and discussion of the hypotheses concerning the evolution of myrmecophily in L. strumosus and other highly adapted myrmecophilous parasites.


Assuntos
Formigas/parasitologia , Besouros/fisiologia , Glândulas Exócrinas/fisiologia , Animais , Besouros/anatomia & histologia , Besouros/ultraestrutura , Glândulas Exócrinas/anatomia & histologia , Microscopia Eletrônica de Varredura , Comportamento Social
7.
Toxicon ; 148: 202-212, 2018 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-29705149

RESUMO

Snakes are the major group of venomous vertebrates, and the rear-fanged snakes represent the vast majority of species and occur worldwide; however, relatively few studies have characterized their venoms and evaluated their potential hazards for humans. Herein we explore the protein composition and properties of the venom of the rear-fanged Green Parrot Snake, Leptophis ahaetulla marginatus, the most common snake found in the Iguazu National Park (Argentina), as well as the main features of its venom delivery system. This species has venom reminiscent of elapid venoms, composed mainly of components such as 3FTxs, CRiSPs and AChE, but it shows low toxicity toward mammals (LD50 > 20 µg/g mouse). The histology of its Duvernoy's venom gland is similar to that of other colubrids, with serous secretory cells arranged in densely packed secretory tubules. The posterior end of its maxilla exhibits 1-3 blade-shaped and slightly recurved fangs but without grooves. This study provides an initial analysis of the biological role of venom in Leptophis, with implications for potential symptoms that might be anticipated from bites by this species.


Assuntos
Colubridae/anatomia & histologia , Glândulas Exócrinas/anatomia & histologia , Venenos de Serpentes/química , Venenos de Serpentes/toxicidade , Animais , Antivenenos/imunologia , Argentina , Dose Letal Mediana , Masculino , Maxila/anatomia & histologia , Camundongos
8.
Toxins (Basel) ; 10(3)2018 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-29533989

RESUMO

Despite numerous studies concerning morphology and venom production and secretion in the main venom gland (and some data on the accessory gland) of the venom glandular apparatus of Viperidae snakes, the primary duct has been overlooked. We characterized the primary duct of the Bothrops jararaca snake by morphological analysis, immunohistochemistry and proteomics. The duct has a pseudostratified epithelium with secretory columnar cells with vesicles of various electrondensities, as well as mitochondria-rich, dark, basal, and horizontal cells. Morphological analysis, at different periods after venom extraction, showed that the primary duct has a long cycle of synthesis and secretion, as do the main venom and accessory glands; however, the duct has a mixed mode venom storage, both in the lumen and in secretory vesicles. Mouse anti-B. jararaca venom serum strongly stained the primary duct's epithelium. Subsequent proteomic analysis revealed the synthesis of venom toxins-mainly C-type lectin/C-type lectin-like proteins. We propose that the primary duct's toxin synthesis products complement the final venom bolus. Finally, we hypothesize that the primary duct and the accessory gland (components of the venom glandular apparatus) are part of the evolutionary path from a salivary gland towards the main venom gland.


Assuntos
Bothrops/metabolismo , Venenos de Crotalídeos/metabolismo , Glândulas Exócrinas/metabolismo , Animais , Bothrops/anatomia & histologia , Glândulas Exócrinas/anatomia & histologia , Glândulas Exócrinas/ultraestrutura , Feminino , Microscopia Eletrônica de Transmissão , Proteômica , Proteínas de Répteis/metabolismo
9.
Nat Commun ; 9(1): 755, 2018 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-29472578

RESUMO

The assassin bug venom system plays diverse roles in prey capture, defence and extra-oral digestion, but it is poorly characterised, partly due to its anatomical complexity. Here we demonstrate that this complexity results from numerous adaptations that enable assassin bugs to modulate the composition of their venom in a context-dependent manner. Gland reconstructions from multimodal imaging reveal three distinct venom gland lumens: the anterior main gland (AMG); posterior main gland (PMG); and accessory gland (AG). Transcriptomic and proteomic experiments demonstrate that the AMG and PMG produce and accumulate distinct sets of venom proteins and peptides. PMG venom, which can be elicited by electrostimulation, potently paralyses and kills prey insects. In contrast, AMG venom elicited by harassment does not paralyse prey insects, suggesting a defensive role. Our data suggest that assassin bugs produce offensive and defensive venoms in anatomically distinct glands, an evolutionary adaptation that, to our knowledge, has not been described for any other venomous animal.


Assuntos
Venenos de Artrópodes/metabolismo , Reduviidae/fisiologia , Animais , Venenos de Artrópodes/genética , Venenos de Artrópodes/toxicidade , Evolução Biológica , Glândulas Exócrinas/anatomia & histologia , Glândulas Exócrinas/metabolismo , Feminino , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Proteínas de Insetos/toxicidade , Masculino , Comportamento Predatório , Proteoma/genética , Proteoma/metabolismo , Reduviidae/anatomia & histologia , Reduviidae/genética , Transcriptoma , Virulência/genética
10.
Arthropod Struct Dev ; 47(2): 162-172, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29438795

RESUMO

This study investigates the neuroanatomy of the defense gland and a related muscle in the stick insect Peruphasma schultei with axonal tracing and histological sections. The gland is innervated by three neurons through the Nervus anterior of the suboesophageal ganglion (SOG), the ipsilateral neuron (ILN), the contralateral neuron (CLN) and the prothoracic intersegmental neuron (PIN). The ILN has a large soma which is typical for motoneurons that cause fast contraction of large muscles and its dendrites are located in motor-sensory and sensory neuropile areas of the SOG. The CLN might be involved in the coordination of bilateral or unilateral discharge as its neurites are closely associated to the ILN of the contralateral gland. Close to the ejaculatory duct of the gland lies a dorsal longitudinal neck muscle, musculus pronoto-occipitalis (Idlm2), which is likely indirectly involved in gland discharge by controlling neck movements and, therefore, the direction of discharge. This muscle is innervated by three ventral median neurons (VMN). Thus, three neuron types (ILN, CLN, and PIN) innervate the gland muscle directly, and the VMNs could aid secretion indirectly. The cytoanatomy of motorneurons innervating the defense gland and neck muscle are discussed regarding the structure and functions of the neuropile in the SOG. As a basis for the neuroanatomical study on the defense gland we assembled a map of the SOG in Phasmatodea.


Assuntos
Insetos/anatomia & histologia , Animais , Glândulas Exócrinas/anatomia & histologia , Feminino , Gânglios/anatomia & histologia , Masculino , Neurônios Motores/citologia , Músculos/anatomia & histologia
11.
Curr Biol ; 28(4): R146-R147, 2018 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-29462577

RESUMO

The euarthropod body consists of serially repeated segments with various degrees of functional specialization and regionalization [1]. Some representatives exhibit deviant metameric patterns expressed as an indirect correspondence between components of the exoskeleton, usually the number or position of dorsoventral sclerotized plates and walking legs (Supplemental Information) [1-3]. Segmental mismatch in the form of supernumerary walking legs per tergite (i.e. dorsal exoskeletal plate) is characteristic of fuxianhuiids, Cambrian euarthropods widely regarded as critical for understanding the origin of this phylum [4,5]. The broader significance of this organization remains obscure, however, due to the difficulty of distinguishing which components of the fuxianhuiid trunk reflect ancestral or derived traits. Here, we describe for the first time the presence of metameric midgut diverticulae in Fuxianhuia protensa from the Chengjiang Konservat-Lagerstätte and demonstrate that these digestive structures follow the segmentation pattern of the dorsal exoskeleton. Midgut diverticulae signal a predatory or scavenging ecology [6,7], falsifying the view of fuxianhuiids as simple mud-feeders [4]. Comparison with other euarthropods [1-3,5] indicates that fuxianhuiids possessed a unique mode of exoskeletal and visceral segmental mismatch, in which the tergites and midgut were segmentally patterned independently from the walking legs and ventral nerve cord. Our findings provide direct evidence of substantial developmental flexibility among stem-group euarthropods during the Cambrian.


Assuntos
Artrópodes/anatomia & histologia , Artrópodes/crescimento & desenvolvimento , Padronização Corporal , Fósseis/anatomia & histologia , Animais , Evolução Biológica , China , Glândulas Exócrinas/anatomia & histologia , Filogenia
12.
Micron ; 104: 66-71, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29102797

RESUMO

The 'samsum ant' Brachyponera sennaarensis is an invasive species in Saudi Arabia, where it forms a serious threat because of its painful sting. As part of a morphological survey of the exocrine system of this species, we studied the mandibular gland of males, queens and workers of this species. The gland of males is similar to the common anatomical appearance the mandibular gland has in ants in general, but is considerably different in queens and workers. In both female castes, the secretory cells are grouped in one single cluster, that is surrounded by a thick sheath of connective tissue. The duct cells, that transport the secretion towards the wrinkled reservoir, appear considerably folded. Both the sheath of connective tissue and the folded ducts are considered as a mechanical reinforcement of the gland, although the reason for such reinforcement remains unclear as we are not aware of any peculiar movements of the mandibles in queens and workers. At the ultrastructural level, the secretory cells in all castes are characterized by a well-developed smooth endoplasmic reticulum, which is indicative for the elaboration of a non-proteinaceous and hence possibly pheromonal secretion. The clear structural differences between males and the two female castes, which so far had not been found in other ant species, show that the mandibular gland in B. sennaarensis most likely has a different caste-dependent function.


Assuntos
Formigas/anatomia & histologia , Formigas/ultraestrutura , Animais , Glândulas Exócrinas/anatomia & histologia , Glândulas Exócrinas/ultraestrutura , Feminino , Masculino , Microscopia , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão
13.
Micron ; 104: 72-79, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29112916

RESUMO

The Dufour's and venom glands are two important exocrine glands in ants. In this study, the morphology and fine structure of these two glands are described in the ant Camponotus japonicus Mayr. The Dufour glands have a characteristic bilobed shape and show a difference in size and color between the female castes (minor and major workers, alate and dealate queens). The external surface of Dufour's gland shows different features among the female castes. It appears more hypertrophied in major workers than in the other castes, indicating for a more pronounced function. The cells of the glandular epithelium in Dufour's gland are characterized by abundant mitochondria, basal invaginations and developed muscle fibres. The venom gland is morphologically similar in the different female castes, and consists of a venom reservoir, a convoluted gland and a bifurcated free secretory filament, with the convoluted gland appearing as a large cap lying on top of the reservoir. Cells of the convoluted gland and the free secretory filaments contain numerous mitochondria and a prominent end apparatus. The results will contribute to understanding the functional morphology of these glands among the different castes in Camponotus ants.


Assuntos
Formigas/anatomia & histologia , Formigas/ultraestrutura , Animais , Glândulas Exócrinas/anatomia & histologia , Glândulas Exócrinas/ultraestrutura , Feminino , Masculino , Microscopia , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão
14.
Sci Rep ; 7(1): 15217, 2017 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-29123242

RESUMO

Global decreases in bee populations emphasize the importance of assessing how environmental stressors affect colony maintenance, especially considering the extreme task specialization observed in honeybee societies. Royal jelly, a protein secretion essential to colony nutrition, is produced by nurse honeybees, and development of bee mandibular glands, which comprise a reservoir surrounded by secretory cells and hypopharyngeal glands that are shaped by acini, is directly associated with production of this secretion. Here, we examined individual and combined effects of the systemic fungicide pyraclostrobin and insecticide fipronil in field-relevant doses (850 and 2.5 ppb, respectively) on mandibular and hypopharyngeal glands in nurse honeybees. Six days of pesticide treatment decreased secretory cell height in mandibular glands. When pyraclostrobin and fipronil were combined, the reservoir volume in mandibular glands also decreased. The total number of acini in hypopharyngeal glands was not affected, but pesticide treatment reduced the number of larger acini while increasing smaller acini. These morphological impairments appeared to reduce royal jelly secretion by nurse honeybees and consequently hampered colony maintenance. Overall, pesticide exposure in doses close to those experienced by bees in the field impaired brood-food glands in nurse honeybees, a change that could negatively influence development, survival, and colony maintenance.


Assuntos
Abelhas/efeitos dos fármacos , Glândulas Exócrinas/efeitos dos fármacos , Ácidos Graxos/metabolismo , Fungicidas Industriais/toxicidade , Inseticidas/toxicidade , Pirazóis/toxicidade , Estrobilurinas/toxicidade , Animais , Abelhas/anatomia & histologia , Abelhas/fisiologia , Glândulas Exócrinas/anatomia & histologia , Glândulas Exócrinas/fisiologia , Histocitoquímica
15.
Proc Biol Sci ; 284(1865)2017 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-29046383

RESUMO

Although various kinds of organic molecules are known to occur in fossils and rocks, most soft tissue preservation in animals is attributed to melanin or porphyrins. Lipids are particularly stable over time-as diagenetically altered 'geolipids' or as major molecular constituents of kerogen or fossil 'geopolymers'-and may be expected to be preserved in certain vertebrate tissues. Here we analysed lipid residues from the uropygial gland of an early Eocene bird using pyrolysis gas chromatography mass spectroscopy. We found a pattern of aliphatic molecules in the fossil gland that was distinct from the host oil shale sediment matrix and from feathers of the same fossil. The fossil gland contained abundant n-alkenes, n-alkanes and alkylbenzenes with chain lengths greater than 20, as well as functionalized long-chain aldehydes, ketones, alkylnitriles and alkylthiophenes that were not detected in host sediment or fossil feathers. By comparison with modern bird uropygial gland wax esters, we show that these molecular fossils are likely derived from endogenous wax ester fatty alcohols and fatty acids that survived initial decay and underwent early diagenetic geopolymerization. These data demonstrate the high fidelity preservation of the uropygial gland waxes and showcase the resilience of lipids over geologic time and their potential role in the exceptional preservation of lipid-rich tissues of macrofossils.


Assuntos
Aves/anatomia & histologia , Glândulas Exócrinas/química , Fósseis/anatomia & histologia , Lipídeos/análise , Animais , Glândulas Exócrinas/anatomia & histologia , Cromatografia Gasosa-Espectrometria de Massas , Paleontologia
16.
Arthropod Struct Dev ; 46(6): 843-868, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28864300

RESUMO

The internal and external anatomy of the posterior metathoracic region, pregenital abdomen, and associated nervous system of the heteropteran infraorder Enicocephalomorpha are thoroughly described, using an array of state-of-the art techniques. Based on morphology, it is hypothesised which modes of communication these insects use. This study is based primarily on an undescribed species of Cocles Bergroth, 1905 (Enicocephalidae) and another undescribed species of Lomagostus Villiers, 1958 (Aenictopecheidae), but additional representatives of the infraorder are also examined. Our results are compared with the literature on other Heteroptera. The metathoracic scent gland system of Enicocephalomorpha uses the same muscles as that of more derived Heteroptera, although the efferent system is different. The presence of a tergal plate and well-developed longitudinal musculature in the families Enicocephalidae and Aenictopecheidae, as well as a sexually dimorphic set of sclerites and membranes that allow an as yet undetermined type of motion, may indicate the presence of vibrational signaling in the infraorder, although experimental confirmation is required. Our findings raise new research questions regarding heteropteran functional morphology and communication.


Assuntos
Comunicação Animal , Heterópteros/anatomia & histologia , Heterópteros/fisiologia , Glândulas Odoríferas/anatomia & histologia , Glândulas Odoríferas/fisiologia , Abdome , Animais , Glândulas Exócrinas/anatomia & histologia , Glândulas Exócrinas/fisiologia , Glândulas Exócrinas/ultraestrutura , Feminino , Heterópteros/ultraestrutura , Masculino , Microscopia Confocal , Microscopia Eletrônica de Varredura , Sistema Nervoso/anatomia & histologia , Glândulas Odoríferas/ultraestrutura
17.
BMC Evol Biol ; 17(1): 128, 2017 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-28587589

RESUMO

BACKGROUND: Sexual selection is thought to promote evolutionary changes and diversification. However, the impact of sexual selection in relation to other selective forces is difficult to evaluate. Male digger wasps of the tribe Philanthini (Hymenoptera, Philanthinae) scent mark territories to attract receptive females. Consequently, the organs for production and storage of the marking secretion, the mandibular gland (MG) and the postpharyngeal gland (PPG), are subject to sexual selection. In female Philanthini, these glands are most likely solely subject to natural selection and show very little morphological diversity. According to the hypothesis that sexual selection drives interspecific diversity, we predicted that the MG and PPG show higher interspecific variation in males than in females. Using histological methods, 3D-reconstructions, and multivariate statistical analysis of morphological characters, we conducted a comparative analysis of the MG and the PPG in males of 30 species of Philanthini and three species of the Cercerini and Aphilanthopsini, two related tribes within the Philanthinae. RESULTS: We found substantial interspecific diversity in gland morphology with regard to gland incidence, size, shape and the type of associated secretory cells. Overall there was a phylogenetic trend: Ensuing from the large MGs and small PPGs of male Cercerini and Aphilanthopsini, the size and complexity of the MG was reduced in male Philanthini, while their PPG became considerably enlarged, substantially more complex, and associated with an apparently novel type of secretory cells. In some clades of the Philanthini the MG was even lost and entirely replaced by the PPG. However, several species showed reversals of and exceptions from this trend. Head gland morphology was significantly more diverse among male than among female Philanthinae. CONCLUSION: Our results show considerable variation in male head glands including the loss of an entire gland system and the evolution of a novel kind of secretory cells, confirming the prediction that interspecific diversity in head gland morphology is higher in male than in female Philanthini. We discuss possible causes for the remarkable evolutionary changes in males and we conclude that this high diversity has been caused by sexual selection.


Assuntos
Evolução Biológica , Vespas/anatomia & histologia , Vespas/genética , Animais , Glândulas Exócrinas/anatomia & histologia , Feminino , Masculino , Mandíbula/metabolismo , Feromônios/metabolismo , Filogenia
18.
Toxins (Basel) ; 9(5)2017 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-28534833

RESUMO

Venoms can deleteriously affect any physiological system reachable by the bloodstream, including directly interfering with the coagulation cascade. Such coagulopathic toxins may be anticoagulants or procoagulants. Snake venoms are unique in their use of procoagulant toxins for predatory purposes. The boomslang (Dispholidus typus) and the twig snakes (Thelotornis species) are iconic African snakes belonging to the family Colubridae. Both species produce strikingly similar lethal procoagulant pathologies. Despite these similarities, antivenom is only produced for treating bites by D. typus, and the mechanisms of action of both venoms have been understudied. In this study, we investigated the venom of D. typus and T. mossambicanus utilising a range of proteomic and bioactivity approaches, including determining the procoagulant properties of both venoms in relation to the human coagulation pathways. In doing so, we developed a novel procoagulant assay, utilising a Stago STA-R Max analyser, to accurately detect real time clotting in plasma at varying concentrations of venom. This approach was used to assess the clotting capabilities of the two venoms both with and without calcium and phospholipid co-factors. We found that T. mossambicanus produced a significantly stronger coagulation response compared to D. typus. Functional enzyme assays showed that T. mossambicanus also exhibited a higher metalloprotease and phospholipase activity but had a much lower serine protease activity relative to D. typus venom. The neutralising capability of the available boomslang antivenom was also investigated on both species, with it being 11.3 times more effective upon D. typus venom than T. mossambicanus. In addition to being a faster clotting venom, T. mossambicanus was revealed to be a much more complex venom composition than D. typus. This is consistent with patterns seen for other snakes with venom complexity linked to dietary complexity. Consistent with the external morphological differences in head shape between the two species, CT and MRI analyses revealed significant internal structural differences in skull architecture and venom gland anatomy. This study increases our understanding of not only the biodiscovery potential of these medically important species but also increases our knowledge of the pathological relationship between venom and the human coagulation cascade.


Assuntos
Colubridae , Venenos de Serpentes , Animais , Antivenenos/farmacologia , Evolução Biológica , Coagulação Sanguínea/efeitos dos fármacos , Colubridae/anatomia & histologia , Colubridae/genética , Colubridae/metabolismo , Glândulas Exócrinas/anatomia & histologia , Humanos , Calicreínas/metabolismo , Metaloproteases/metabolismo , Fosfolipases A2/metabolismo , Proteômica , Proteínas de Répteis/metabolismo , Crânio/anatomia & histologia , Venenos de Serpentes/metabolismo , Venenos de Serpentes/farmacologia
19.
Anat Rec (Hoboken) ; 300(8): 1420-1428, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28388015

RESUMO

An avian uropygial gland is located on the mid-dorsum of the tail, and is the only external gland found in birds. Most studies have focused on the function, gross anatomy and chemical nature of this gland, with little research on its ontogeny. The purpose of this study was to examine the development of this gland in a series of Laysan Albatross (Phoebastria immutabilis) embryos. Specimens were examined anatomically and histologically. It was found that grooves preceded glandular development by many stages. The embryogenesis of the uropygial gland was divided into 6 phases: preinception, groove inception, mesodermal separation, migrating mesodermal cells, oval shaped "depressions", constriction and finally glandular inception. No other gland is known to develop similarly, though there may be parallels with femoral gland development. In comparison to other bird species, the length of the development period in the Albatross, as well as other compounding factors, make it difficult to determine the significance of these observations. The development of a mesodermal band, soon to be a connective tissue capsule, is more complex than originally described in ducks. Thus, the unique nature of this gland is established, but the significance of the observations required further studies into uropygial gland development. Anat Rec, 300:1420-1428, 2017. © 2017 Wiley Periodicals, Inc.


Assuntos
Aves/anatomia & histologia , Aves/embriologia , Desenvolvimento Embrionário/fisiologia , Glândulas Exócrinas/anatomia & histologia , Glândulas Exócrinas/embriologia , Animais
20.
PLoS One ; 12(2): e0172047, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28187210

RESUMO

Euchambersia mirabilis is an iconic species of Permo-Triassic therapsid because of its unusually large external maxillary fossa linked through a sulcus to a ridged canine. This anatomy led to the commonly accepted conclusion that the large fossa accommodated a venom gland. However, this hypothesis remains untested so far. Here, we conducted a µCT scan assisted reappraisal of the envenoming capacity of Euchambersia, with a special focus on the anatomy of the maxillary fossa and canines. This study shows that the fossa, presumably for the venom-producing gland, is directly linked to the maxillary canal, which carries the trigeminal nerve (responsible for the sensitivity of the face). The peculiar anatomy of the maxillary canal suggests important reorganisation in the somatosensory system and that a ganglion could possibly have been present in the maxillary fossa instead of a venom gland. Nevertheless, the venom gland hypothesis is still preferred since we describe, for the first time, the complete crown morphology of the incisiform teeth of Euchambersia, which strongly suggests that the complete dentition was ridged. Therefore Euchambersia manifests evidence of all characteristics of venomous animals: a venom gland (in the maxillary fossa), a mechanism to deliver the venom (the maxillary canal and/or the sulcus located ventrally to the fossa); and an apparatus with which to inflict a wound for venom delivery (the ridged dentition).


Assuntos
Glândulas Exócrinas/anatomia & histologia , Fósseis/anatomia & histologia , Maxila/anatomia & histologia , Peçonhas/metabolismo , Animais , Dentição , Glândulas Exócrinas/diagnóstico por imagem , Fósseis/diagnóstico por imagem , Maxila/diagnóstico por imagem , Répteis , Microtomografia por Raio-X
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