The Experts below are selected from a list of 153 Experts worldwide ranked by ideXlab platform
Mary Bownes - One of the best experts on this subject based on the ideXlab platform.
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conservation and divergence in the control of yolk protein genes in dipteran insects
Development Genes and Evolution, 1997Co-Authors: Claudia Tortiglione, Mary BownesAbstract:We have investigated the conservation of regulatory elements for sex- and tissue-specific gene expression in three dipteran species, Drosophila melanogaster, Musca domestica and Calliphora erythrocephala, using the yolk protein (yp) genes. Yolk proteins of the fruitfly, medfly, housefly and blowfly are very well conserved both in their sequence and their expression in ovarian follicle cells and in fat bodies of adult females. Furthermore, yp regulation by both hormonal and nutritional factors shows similar features in all four species. To study conservation of yp regulation in dipteran insects, we tested 5′ flanking regions from one Musca yp gene and one Calliphora yp gene for enhancer functions in D. melanogaster. Two fragments of 823 and 1046 bp isolated from Musca and Calliphora yp genes, respectively, are able to direct correct expression of a reporter gene in the ovarian follicle cells of transformed Drosophila at specific stages during oogenesis. Surprisingly, these enhancers do not confer sex-specific reporter gene expression in the fat body, as expression was found in both sexes of the transformed flies. None-the-less by in vitro DNA/protein interaction assays, a 284-bp DNA region from the Musca yp enhancer was able to bind the Drosophila DOUBLESEX (DSX) protein, which in D.melanogaster confers sex-specific expression of yp. We speculate that the sex-determining pathway is not directly involved in yp regulation in Musca or Calliphora adult females, but depends instead on hormonal controls to achieve sex-specific expression of yp genes in the adult.
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The sequence and expression pattern of the Calliphora erythrocephala yolk protein A and B genes.
Journal of molecular evolution, 1994Co-Authors: Alberto Martinez, Mary BownesAbstract:The yolk protein genes (yps) are expressed in a temporal, tissue- and sex-specific fashion in Drosophila melanogaster. Here we report the sequence of two related genes in Calliphora erythrocephala. The predicted Calliphora yolk protein (YP) sequences are well conserved, especially at the C-terminal end when compared to those of D. melanogaster and Ceratitis capitata. Database searches with the Calliphora yolk protein B (CeYPB) sequence identify the vertebrate lipase similarity reported for the YPs of Drosophila and Ceratitis. Moreover, sequences with identity to divalent ion-binding sites were observed, which colocalized with putative tyrosine sulfation sites. Calliphora oogenesis differs from Drosophila in that it is cyclic in response to a meat feed. The Calliphora yp genes are expressed in the follicle cells of the egg chamber during vitellogenesis, as shown by in situ hybridization, and the yp message levels correlate with YP synthesis. The synthesis of the yp transcripts in ovaries of Calliphora occurs in the same pattern as that for ovarian transcripts in Drosophila. In the carcass, yp transcript levels are correlated with the production of a batch of eggs.
Klaus Scheller - One of the best experts on this subject based on the ideXlab platform.
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Conservation of Hexamerin Endocytosis in Diptera
European journal of biochemistry, 1997Co-Authors: Klaus SchellerAbstract:In cyclorrhaphan Diptera at least two different types of haemolymph proteins exist which belong to the class of hexamerins. In the last larval instar of Calliphora vicina, the highly aromatic hexamerin, arylphorin, and the second hexamerin, PII, make up about 90% of haemolymph proteins. Both of these proteins are selectively taken up by the fat body cells at the end of larval life and share a common membrane-bound receptor. In addition, hexamerins and possible hexamerin receptors of Calliphora vicina, Calliphora vomitoria, Drosophila melanogaster, Ceratitis capitata, Sarcophaga bullata, Musca domestica and Protophormia terraenovae were investigated. Uptake of arylphorin by the larval fat bodies of Calliphora vicina as well asarylphorin-receptor binding can be competed in vitro by haemolymph from other Diptera. Therefore, hexamerin-receptor binding must be conserved among related cyclorrhaphan Diptera and between different types of hexamerins within a species. As the degree of competition is in good agreement with the presumed phylogenetic distances between these species, the method described here provides a simple tool to estimate evolutionary distances.
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Quaternary and subunit structure of Calliphora arylphorin as deduced from electron microscopy, electrophoresis, and sequence similarities with arthropod hemocyanin
Journal of Comparative Physiology B, 1992Co-Authors: Jürgen Markl, Heinz Decker, Anette Savel-niemann, J. Robin Harris, Michaela Süling, Ulrike Naumann, Klaus SchellerAbstract:Arylphorin was purified from larvae of the blowfly Calliphora vicina and studied in its oligomeric form and after dissociation at pH 9.6 into native subunits. In accordance with earlier literature, it was electrophoretically shown to be a 500 kDa hexamer (1×6) consisting of 78 kDa polypeptides (= subunits). Electron micrographs of negatively stained hexamers show a characteristic curvilinear, equilateral triangle of 12 nm in diameter (top view) and a rectangle measuring 10×12 nm (side view). Alternatively, particles in the top view orientation exhibit a roughly circular shape 12 nm in diameter. Crossed immunoelectrophoresis revealed the presence of a major subunit type; the nature of a very minor and a third immunologically separated component remains unclear. A novel 2×6 arylphorin particle was detected and isolated. It comprises less than 10% of the total arylphorin material and shows a long, narrow interhexamer bridge in the electron microscope. An arylphorin dissociation intermediate identified as a trimer (1/2×6) was isolated; its possible quaternary structure is discussed on the basis of electron micrographs. The epitope of monoclonal antibody Ec-7 directed against tarantula ( Eurypelma californicum ) hemocyanin subunit d and also reactive to Calliphora arylphorin was traced to a highly conserved peptide of 27 amino acids localized in the center of the protein. The primary structure of Calliphora arylphorin as published in our preceding paper (Naumann and Scheller 1991) is compared in detail to the sequences of spider and spiny lobster hemocyanin. This revealed a basic framework of 103 strictly conserved amino acids. Isofunctional exchanges are proposed for another 76 positions. On the basis of these similarities, and the published three-dimensional model of spiny lobster hemocyanin, a detailed model of the quaternary structure of Calliphora arylphorin is presented. A second larval storage protein previously termed protein II was purified from Calliphora hemolymph. It was demonstrated to be a 500 kDa hexamer of 83 kDa subunits. In the electron microscope it shows a cubic view 9 nm in length with a large central hole and a rectangular view (9×10 nm) with a large central cavity. A morphologically very similar hemolymph protein was detected in Drosophila melanogaster larvae. From its structural appearance it is uncertain whether protein II belongs to the hemocyanin superfamily or not.
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Complete cDNA and gene sequence of the developmentally regulated arylphorin of Calliphora vicina and its homology to insect hemolymph proteins and arthropod hemocyanins.
Biochemical and biophysical research communications, 1991Co-Authors: Ulrike Naumann, Klaus SchellerAbstract:Two cDNA libraries were prepared from poly(A)+ RNA isolated from fat bodies of last instar larvae of the blowfly Calliphora vicina. The libraries were probed with a genomic clone containing the coding sequence for an arylphorin subunit. Two cDNA clones as well as the genomic clone were mapped and their nucleotide sequences were determined. This revealed the presence of an open reading frame corresponding to a polypeptide with 759 amino acid residues. The deduced primary structure of Calliphora arylphorin and hemolymph proteins of other insect species and arthropod hemocyanine show nearly 30% identity. Highly conserved regions could be also identified.
Roland Spies - One of the best experts on this subject based on the ideXlab platform.
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marked for life muscle attachment site patterns in blowfly larvae are constant throughout development
Parasitology Research, 2013Co-Authors: Senta Niederegger, Anton Miroschnikow, Roland SpiesAbstract:The muscular attachment sites (MAS) of blowfly larvae can be visualised as “dots” by removing and staining the cuticle. Each segment bears several rows of MAS. The silhouettes of a subset of those rows in the second, third, and fourth segments were previously shown to be specific for four species of L3 blowfly larvae. In this investigation, the MAS patterns are described for a fifth species (Protophormia terraenovae) and throughout larval development of Calliphora vicina and Calliphora vomitoria. The patterns of P. terraenovae show considerable differences to those of the Calliphora species (larger MAS, characteristic “M” shape in row 4A), thus providing further evidence for the viability of the method as tool for species determination. Larvae with a body length of only 3 mm already show a complete set of MAS expressing identical pattern characteristics as L3 larvae with maximal body length. These characteristics are largely unchanged throughout development. Plotting the row length as a function of the body length throughout development reveals a linear correlation. Therefore, in case of requirement (e.g. fragmentation), not only the species but also the approximate larval age can be calculated with this method.
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anatomy of the stomatogastric nervous system associated with the foregut in drosophila melanogaster and Calliphora vicina third instar larvae
Journal of Morphology, 2008Co-Authors: Roland Spies, Andreas Schoofs, Hans-georg HeinzelAbstract:The stomatogastric nervous system (SNS) associated with the foregut was studied in 3rd instar larvae of Drosophila melanogaster and Calliphora vicina (blowfly). In both species, the foregut comprises pharynx, esophagus, and proventriculus. Only in Calliphora does the esophagus form a crop. The position of nerves and neurons was investigated with neuronal tracers in both species and GFP expression in Drosophila. The SNS is nearly identical in both species. Neurons are located in the proventricular and the hypocerebral ganglion (HCG), which are connected to each other by the proventricular nerve. Motor neurons for pharyngeal muscles are located in the brain not, as in other insect groups, in the frontal ganglion. The position of the frontal ganglion is taken by a nerve junction devoid of neurons. The junction is composed of four nerves: the frontal connectives that fuse with the antennal nerves (ANs), the frontal nerve innervating the cibarial dilator muscles and the recurrent nerve that innervates the esophagus and projects to the HCG. Differences in the SNS are restricted to a crop nerve only present in Calliphora and an esophageal ganglion that only exists in Drosophila. The ganglia of the dorsal organs give rise to the ANs, which project to the brain. The extensive conformity of the SNS of both species suggests functional parallels. Future electrophysiological studies of the motor circuits in the SNS of Drosophila will profit from parallel studies of the homologous but more accessible structures in Calliphora.
Armin Huber - One of the best experts on this subject based on the ideXlab platform.
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Rhodopsin patterning in central photoreceptor cells of the blowfly Calliphora vicina: cloning and characterization of Calliphora rhodopsins Rh3, Rh5 and Rh6.
Journal of Experimental Biology, 2005Co-Authors: Angelika Schmitt, Reinhard Paulsen, Andreas Vogt, Katrin Friedmann, Armin HuberAbstract:The ommatidia that constitute the compound eyes of flies contain eight photoreceptor cells, which are divided into two classes: the peripheral photoreceptors, R1-6, and the central photoreceptors, R7 and R8. In the fruit fly, Drosophila, R1-6 express the same rhodopsin (Rh1), whilst the R7 and R8 of a given ommatidium express either Rh3 and Rh5, or Rh4 and Rh6, respectively. We have studied whether this expression pattern of rhodopsins is conserved in the blowfly Calliphora vicina. We have cloned three novel Calliphora rhodopsins, which are homologues of Drosophila Rh3, Rh5 and Rh6, with an amino acid sequence identity of 80.7%, 60.9% and 86.1%, respectively. Immunocytochemical studies with antibodies specific for Rh3, Rh5 and Rh6 revealed that Rh3 is expressed in a subset of R7 cells, while Rh5 and Rh6 are expressed in a non-overlapping subset of R8 cells. Rh3 and Rh5 are present in most cases in the same ommatidia, which account for approximately 27% of all ommatidia, and Rh6 is found in the complementary 73%. The similarity of the rhodopsin expression pattern of Calliphora with that of Drosophila suggests that the developmental mechanism regulating the terminal differentiation of R7 and R8 cells are highly conserved between these fly species.
Ali Ozbandi - One of the best experts on this subject based on the ideXlab platform.
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Wound Myiasis in a Flamingo (Phoenicopterus ruber) Caused by Calliphora spp. Larvae from Northwest of Iran: A Case Report.
Iranian journal of parasitology, 2018Co-Authors: Roghayeh Norouzi, Saeed Kahnamooie, Ali OzbandiAbstract:Myiasis is the infestation of animals or man tissues by parasitic dipterous fly larvae. Wound myiasis is the result of fly egg deposition on decaying flesh or pus discharging wounds. This case report describes a type of wound myiasis caused by Calliphora spp. in a Flamingo (Phoenicopterus ruber) from East Azerbaijan Province, Iran. A 3-yr-old female Flamingo was suffering in its left wing leading to an extensive discharging wound, which was heavily infested by maggots (fly larvae). The examination of external morphological characters of the second and third-instar larvae, posterior spiracles and internal cephalopharyngeal skeleton, led to the identification of the Calliphora spp. fly genus. Treatment consisted of removal of the larvae and surgical debridement, then spray of antibiotic and toxic drug. Following removal of larvae and treatment, the symptoms completely resolved within the last hour and remained asymptomatic several weeks later. This is the first report of wound myiasis in a Flamingo (Phoenicopterus ruber) by the facultative myiasis agent Calliphora spp. in Iran and the world.
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Wound Myiasis in a Flamingo (Phoenicopterus ruber) Caused by Calliphora spp. Larvae from Northwest of Iran: A Case Re-port
Tehran University of Medical Sciences, 2018Co-Authors: Roghayeh Norouzi, Saeed Kahnamooie, Ali OzbandiAbstract:Myiasis is the infestation of animals or man tissues by parasitic dipterous fly larvae. Wound myiasis is the result of fly egg deposition on decaying flesh or pus discharging wounds. This case report describes a type of wound myiasis caused by Calliphora spp. in a Flamingo (Phoenicopterus ruber) from East Azerbaijan Province, Iran. A 3-yr-old female Flamingo was suffering in its left wing leading to an extensive discharging wound, which was heavily infested by maggots (fly larvae). The examination of external morphological characters of the second and third-instar larvae, posterior spiracles and internal cephalopharyngeal skeleton, led to the identification of the Calliphora spp. fly genus. Treatment consisted of removal of the larvae and surgical debridement, then spray of antibiotic and toxic drug. Following removal of larvae and treatment, the symptoms completely resolved within the last hour and remained asymptomatic several weeks later. This is the first report of wound myiasis in a Flamingo (Phoenicopterus ruber) by the facultative myiasis agent Calliphora spp. in Iran and the world
