Search results for "Arthropod"
showing 10 items of 308 documents
Toxic Proteins and Peptides
1994
Many animals produce poisonous substances which, even at a relatively low dose, are deleterious or lethal to other organisms, including man. They may serve on the one hand to disable or kill prey, or on the other hand as a protection or defence against predators. These substances are mostly produced by special glands, and both poison reservoirs and specialized structures for delivering the secretion, e.g. stings or modified mouthparts or fangs, are usually also present. In accordance with the aims of this book, we will deal with the comparative biochemistry of the animal toxins as natural products with special structures and functions; a discussion of the mechanisms of their pharmacological…
The fine structural organization of sternal glands of pseudergates and workers in termites (Isoptera): a comparative survey
2008
1873-5495 (Electronic) Comparative Study Journal Article; Thirty-nine species belonging to different families of termites are studied to give a comprehensive view of the evolution of the sternal glands. Several modifications occurring at cuticular and cytological levels are described in neuter castes. The outer epicuticle is always pierced by epicuticular pores. In advanced termites the epicuticular filaments greatly increase in number and length creating a thick layer. The pore canals gradually enlarge while the cuticle changes into a lattice structure lining an extracellular space in which the secretion is stored. Two classes of cells are present in basal termites (Mastotermitidae, Hodote…
Functional consequences of prey acclimation to ocean acidification for the prey and its predator
2016
Ocean acidification is the suite of chemical changes to the carbonate system of seawater as a consequence of anthropogenic carbon dioxide (CO2) emissions. Despite a growing body of evidences demonstrating the negative effects of ocean acidification on marine species, the consequences at the ecosystem level are still unclear. One factor limiting our ability to upscale from species to ecosystem is the poor mechanistic understanding of the functional consequences of the observed effects on organisms. This is particularly true in the context of species interactions. The aim of this work was to investigate the functional consequence of the exposure of a prey (the mussel Brachidontes pharaonis) t…
Quaternary structure and molecular model of a 4x6mer arthropod hemocyanin in oxygenated and deoxygenated states by 3D cryo-electron microscopy
2007
Extended abstract of a paper presented at MC 2007, 33rd DGE Conference in Saarbrücken, Germany, September 2 – September 7, 2007
Review of the genus Valdasus Stål, 1860 (Heteroptera, Miridae, Cylapinae), with descriptions of four new species from Brazil, Ecuador and French Guia…
2020
The genus Valdasus Stål, 1860 is reviewed. Four species are described as new: Valdasus favrei n. sp., V. ferrerai n. sp., V. flavinotum n. sp., and V. henryi n. sp. V. erebeus Distant, 1883 and V. stygius Distant, 1883 are transferred again to Valdasus (original combination reestablished) from Peltidocylapus Poppius and they are redescribed along with the type species V. schoenherri Stål, 1860. Presence of V. bolivianus in Argentina is challenged after new analysis of female specimen mentioned in literature.
A cluster of cuticle protein genes of Drosophila melanogaster at 65A: sequence, structure and evolution
1997
0016-6731 (Print) Journal Article Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S.; A 36-kb genomic DNA segment of the Drosophila melanogaster genome containing 12 clustered cuticle genes has been mapped and partially sequenced. The cluster maps at 65A 5-6 on the left arm of the third chromosome, in agreement with the previously determined location of a putative cluster encompassing the genes for the third instar larval cuticle proteins LCP5, LCP6 and LCP8. This cluster is the largest cuticle gene cluster discovered to date and shows a number of surprising features that explain in part the genetic complexity of the LCP5, LCP6 and LCP8 loci. The genes encoding LCP5 a…
A hemocyanin from the Onychophora and the emergence of respiratory proteins
2002
The velvet worms (Onychophora) are considered living fossils and are closely related to the Euarthropoda. Onychophora possess a tracheal system for respiratory function, but oxygen-transport proteins have been considered unnecessary. Here, we show that the hemolymph of the Epiperipatus sp. (Onychophora: Peripatidae) contains an arthropod-type hemocyanin, demonstrating that such protein exists outside the Euarthropoda. Thus, the evolution of oxygen carriers preceded the divergence of the Onychophora and Euarthropoda and was most likely linked to the evolution of an efficient circulatory system in a low-oxygen environment. The cDNA of the Epiperipatus hemocyanin subunit comprises 2,287 bp an…
Putative phenoloxidases in the tunicate Ciona intestinalis and the origin of the arthropod hemocyanin superfamily.
2003
In addition to the respiratory copper-containing proteins for which it is named, the arthropod hemocyanin superfamily also includes phenoloxidases and various copperless storage proteins (pseudo-hemocyanins, hexamerins and hexamerin receptors). It had long been assumed that these proteins are restricted to the arthropod phylum. However, in their analysis of the predicted genes in the Ciona intestinalis (Urochordata:Tunicata) genome, Dehal et al. (Science 298:2157–2167) proposed that the sea squirt lacks hemoglobin but uses hemocyanin for oxygen transport. While there are, nevertheless, four hemoglobin genes present in Ciona, we have identified and cloned two cDNA sequences from Ciona that i…
Manipulating mtDNA in vivo reprograms metabolism via novel response mechanisms.
2019
Mitochondria have been increasingly recognized as a central regulatory nexus for multiple metabolic pathways, in addition to ATP production via oxidative phosphorylation (OXPHOS). Here we show that inducing mitochondrial DNA (mtDNA) stress in Drosophila using a mitochondrially-targeted Type I restriction endonuclease (mtEcoBI) results in unexpected metabolic reprogramming in adult flies, distinct from effects on OXPHOS. Carbohydrate utilization was repressed, with catabolism shifted towards lipid oxidation, accompanied by elevated serine synthesis. Cleavage and translocation, the two modes of mtEcoBI action, repressed carbohydrate rmetabolism via two different mechanisms. DNA cleavage activ…
Revision of the plant bug genus Xenocylapidius (Hemiptera, Heteroptera, Miridae, Cylapinae), with descriptions of five new species from Australia and…
2014
Abstract The genus Xenocylapidius Gorczyca, 1997 is revised. Five new species: Xenocylapidius acutipennis sp. n., Xenocylapidius ater sp. n., Xenocylapidius bimaculatus sp. n., Xenocylapidius gemellus sp. n., and Xenocylapidius rolandi sp. n. are described from Australia and New Caledonia. Illustrations of the male genitalia, color photographs of dorsal and lateral views of the adults of all species, and key to species of the genus Xenocylapidius are provided.