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Arthropod Structure & Development

Doris L Maurer, Tobias Kohl, Michael J Gebhardt
The stick insect Peruphasma schultei stands out from other insects by its deep matt black cuticle. We tested whether the appearance of P. schultei is due to microstructures of the cuticle, a phenomenon that has recently been described for the velvet black scales of the Gaboon viper. The shiny black stick insect Anisomorpha paromalus served as a control. We found that the P. schultei cuticle is characterised by two different types of microstructures, tall elevations with a maximum size of 18 μm and small structures with a height of 4 μm...
November 23, 2016: Arthropod Structure & Development
Bo-Kai Liao, Andrew C Oates
Modular body organization is found widely across multicellular organisms, and some of them form repetitive modular structures via the process of segmentation. It's vastly interesting to understand how these regularly repeated structures are robustly generated from the underlying noise in biomolecular interactions. Recent studies from arthropods reveal similarities in segmentation mechanisms with vertebrates, and raise the possibility that the three phylogenetic clades, annelids, arthropods and chordates, might share homology in this process from a bilaterian ancestor...
November 22, 2016: Arthropod Structure & Development
Aleksei A Miroliubov
Rhizocephalan parasites have a peculiar life cycle, and their adults lost almost all traits found usually in Crustacea. Despite some data on anatomy and ultrastructure of interna of Peltogastridae, some crucial aspects of morphology are still unknown. For example, there is only one mentioning of myocytes found in interna of Rhizophalans (Sacculina carcini). So we aimed at studying the muscular system of the interna of Peltogaster paguri using serial histological sectioning and fluorescent staining (TRITC-labelled phalloidin) with confocal microscopy...
November 18, 2016: Arthropod Structure & Development
Julia V A Figueiredo, André L P Perondini, Denise Selivon
The chorion internal structure of the Anastrepha eggs from 16 species of different infrageneric taxonomic groups is described by scanning and transmission electron microscopy analyses. The chorion has structural similarities of layers, and is cavernous along the entire length of the eggs. Despite these similarities, an additional trabecular layer (ATL) exists in some species that, together with other characteristics, allow the recognition of four patterns of chorion structuring. Pattern I, in which the ATL layer is absent, was found in A...
November 12, 2016: Arthropod Structure & Development
Philip O M Steinhoff, Andy Sombke, Jannis Liedtke, Jutta M Schneider, Steffen Harzsch, Gabriele Uhl
Jumping spiders are known for their extraordinary cognitive abilities. The underlying nervous system structures, however, are largely unknown. Here, we explore and describe the anatomy of the brain in the jumping spider Marpissa muscosa (Clerck, 1757) by means of paraffin histology, X-ray microCT analysis and immunohistochemistry as well as three-dimensional reconstruction. In the prosoma, the CNS is a clearly demarcated mass that surrounds the esophagus. The anteriormost neuromere, the protocerebrum, comprises nine bilaterally paired neuropils, including the mushroom bodies and one unpaired midline neuropil, the arcuate body...
November 11, 2016: Arthropod Structure & Development
Yanina-Yasmin Pesch, Dietmar Riedel, Matthias Behr
The architecture of the outer body wall cuticle is fundamental to protect arthropods against invading pathogens and numerous other harmful stresses. Such robust cuticles are formed by parallel running chitin microfibrils. Molting and also local wounding leads to dynamic assembly and disassembly of the chitin-matrix throughout development. However, the underlying molecular mechanisms that organize proper chitin-matrix formation are poorly known. Recently we identified a key region for cuticle thickening at the apical cell surface, the cuticle assembly zone, where Obstructor-A (Obst-A) coordinates the formation of the chitin-matrix...
November 7, 2016: Arthropod Structure & Development
Polona Mrak, Urban Bogataj, Jasna Štrus, Nada Žnidaršič
The crustacean cuticle is a chitin-based extracellular matrix, produced in general by epidermal cells and ectodermally derived epithelial cells of the digestive tract. Cuticle morphogenesis is an integrative part of embryonic and postembryonic development and it was studied in several groups of crustaceans, but mainly with a focus on one selected aspect of morphogenesis. Early studies were focused mainly on in vivo or histological observations of embryonic or larval molt cycles and more recently, some ultrastructural studies of the cuticle differentiation during development were performed...
November 2, 2016: Arthropod Structure & Development
Jonas O Wolff, Michael Seiter, Stanislav N Gorb
The cuticle of arthropods is usually composed of layers of a chitin-protein-microcomposite, a proteinacous epicuticle and a thin lipid coating. However, in some instances a thick cement layer (cerotegument) covers the cuticle and may produce elaborate microstructures. This has previously been described for millipedes and mites. Here we report the previously unknown presence of a superhydrophobic cerotegument in whip-spiders (Ambypygi) and reveal its variation in ultrastructure and water-repellence between species...
October 14, 2016: Arthropod Structure & Development
Alberto Jorge, Carlo Polidori, Javier Garcia-Guinea, José Luis Nieves-Aldrey
The inclusion of Zn in insect mandibles affects their hardness and is functional to their use during feeding or reproducing. However, little is known on the chemical/structural base of Zn enrichment. Here, we found that cathodoluminescence (CL) technique revealed two different types of CL spectra in the mandibles of Hymenoptera, depending on the Zn enrichment level assessed by Energy Dispersive X-ray Spectroscopy (EDS). Individuals having negligible traces to low % of Zn in their mandible teeth (≤3 wt%) presented a wide band of luminescence in the visible range which resembled those observed in the CC structures of graphite...
October 11, 2016: Arthropod Structure & Development
Frank W Smith, Bob Goldstein
The origin and diversification of segmented metazoan body plans has fascinated biologists for over a century. The superphylum Panarthropoda includes three phyla of segmented animals-Euarthropoda, Onychophora, and Tardigrada. This superphylum includes representatives with relatively simple and representatives with relatively complex segmented body plans. At one extreme of this continuum, euarthropods exhibit an incredible diversity of serially homologous segments. Furthermore, distinct tagmosis patterns are exhibited by different classes of euarthropods...
October 7, 2016: Arthropod Structure & Development
Ralf Janssen
This paper summarizes our current knowledge on the expression and assumed function of Drosophila and (other) arthropod segmentation gene orthologs in Onychophora, a closely related outgroup to Arthropoda. This includes orthologs of the so-called Drosophila segmentation gene cascade including the Hox genes, as well as other genetic factors and pathways involved in non-drosophilid arthropods. Open questions about and around the topic are addressed, such as the definition of segments in onychophorans, the unclear regulation of conserved expression patterns downstream of non-conserved factors, and the potential role of mesodermal patterning in onychophoran segmentation...
October 7, 2016: Arthropod Structure & Development
Maria Kupper, Christian Stigloher, Heike Feldhaar, Roy Gross
The bacterial endosymbiont Blochmannia floridanus of the carpenter ant Camponotus floridanus contributes to its hosts' ontogeny via nutritional upgrading during metamorphosis. This primary endosymbiosis is essential for both partners and vertical transmission of the endosymbionts is guaranteed by bacterial infestation of oocytes. Here we present a detailed analysis of the presence and localisation of B. floridanus in the ants' ovaries obtained by FISH and TEM analyses. The most apical part of the germarium harbouring germ-line stem cells (GSCs) is not infected by the bacteria...
October 6, 2016: Arthropod Structure & Development
Terri A Williams, Lisa M Nagy
No abstract text is available yet for this article.
October 5, 2016: Arthropod Structure & Development
Friedrich-Wilhelm Schürmann
In the insect brain, mushroom bodies represent a prominent central neuropil for multisensory integration and, crucially, for learning and memory. For this reason, special attention has been focused on its small chemical synapses. Early studies on synaptic types and their distribution, using conventional electron microscopy, and recent publications have resolved basic features of synaptic circuits. More recent studies, using experimental methods for resolving neurons, such as immunocytochemistry, genetic labelling, high resolution confocal microscopy and more advanced electron microscopy, have revealed many new details about the fine structure and molecular contents of identifiable neurons of mushroom bodies and has led to more refined modelling of functional organisation...
October 5, 2016: Arthropod Structure & Development
Laura Vannini, Judith H Willis
The largest Arthropod cuticular protein family, CPR, has the Rebers and Riddiford (R&R) Consensus that in an extended form confers chitin-binding properties. Two forms of the Consensus, RR-1 and RR-2, have been recognized and initial data suggested that the RR-1 and RR-2 proteins were present in different regions within the cuticle itself. Thus, RR-2 proteins would contribute to exocuticle that becomes sclerotized, while RR-1s would be found in endocuticle that remains soft. An alternative, and more common, suggestion is that RR-1 proteins are used for soft, flexible cuticles such as intersegmental membranes, while RR-2s are associated with hard cuticle such as sclerites and head capsules...
October 4, 2016: Arthropod Structure & Development
Emanuele Ranieri, Sara Ruschioni, Paola Riolo, Nunzio Isidoro, Roberto Romani
The meadow spittlebug, Philaenus spumarius (L.) (Hemiptera: Cercopoidea: Aphrophoridae), is a polyphagous species that transmits Xylella fastidiosa, a bacterium associated with "Olive Quick Decline Syndrome" in Southern Italy. In this study, the morphology and the ultrastructure of the antennal sensilla of P. spumarius were investigated. The antennae consist of three segments: a basal scape, a pedicel and a flagellum composed of a basal enlargement (ampulla) and a long segment (filament). The pedicel bears a single campaniform sensillum while the ampulla houses twelve coeloconic sensilla and three large basiconic sensilla...
October 3, 2016: Arthropod Structure & Development
Alexey A Polilov, Alexey S Shmakov
A new set of data on the internal and external structure of the adult and larva of the thrips Heliothrips haemorrhoidalis (Bouché, 1833) is presented. The structure of the internal systems of this thrips was revealed using modern methods of 3D computer modelling. The changes in shape and relative size are discussed as an outcome of miniaturization in comparison to the supposed ancestor of this species. The layout of the internal systems of thrips is compared to those of other insects similar in size: beetles of the families Ptiliidae and Corylophidae and wasps of the families Mymaridae and Trichogrammatidae...
September 28, 2016: Arthropod Structure & Development
Izabela Jędrzejowska, Kamil Szymusiak, Marta Mazurkiewicz-Kania, Arnold Garbiec
Scorpions are viviparous matrotrophic arthropods. Both, fertilization and embryonic development occur in the female gonad called ovariuterus. Two distinct reproductive patterns are recognized among scorpions: apoikogenic and katoikogenic. In the ovariuterus of apoikogenic scorpions growing oocytes protrude from the ovarian wall and continue previtellogenic and vitellogenic growth on the gonad surface being accompanied by the follicular cells that cover the oocyte surface, and, in most families, the stalk cells that join the oocyte with the ovariuterus wall...
September 27, 2016: Arthropod Structure & Development
Daniel B Zurek, Stanislav N Gorb, Dagmar Voigt
Insects live in a three-dimensional space, and need to be able to attach to different types of surfaces in a variety of environmental and behavioral contexts. Adult leaf beetles possess great attachment ability due to their hairy attachment pads. In contrast, their larvae depend on smooth pads to attach to the same host plant. We tested friction forces generated by larvae and adults of dock leaf beetles Gastrophysa viridula on different rough surfaces, and found that adults generate much higher attachment to various substrates than larvae, but are more susceptible to completely losing attachment ability on surfaces with "critical" roughness...
September 21, 2016: Arthropod Structure & Development
James B Nardi, Charles M Bee, Steven J Taylor
The gut lumen of the arthropod detritivore provides hospitable and multifaceted environments for diverse assemblages of microbes. Many microbes, including trichomycetes fungi, bacteria, and archaea establish stable, adherent communities on the cuticular surface secreted by the hindgut epithelium. Regional differences in the surface topography within the hindgut of a given millipede are reflected in differing and diverse microbial assemblages. The spirostreptid millipede Cambala speobia is a detritivore found on the floors of Texas caves...
September 13, 2016: Arthropod Structure & Development
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