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81.
Mahmood S.?ShivjiEmail author Demian D.?Chapman Ellen K.?Pikitch Paul W.?Raymond 《Conservation Genetics》2005,6(6):1035-1039
Great white sharks are protected by national legislation in several countries, making this species the most widely protected
elasmobranch in the world. Although the market demand for shark fins in general has continued to grow, the value and extent
of utilization of white shark fins in trade has been controversial. We combine law enforcement with genetic profiling to demonstrate
that illegal trade in fins of this species is occurring in the contemporary international market. Furthermore, we document
the presence of fins from very young white sharks in the trade, suggesting a multiple-use market (food to trophies) exists
for fins of this species. The presence of small fins in the trade contradicts the view that white shark fins have market value
only as large display trophies, and not as food. Our findings indicate that effective conservation of protected shark species
will require international management regimes that include monitoring of the shark fishery and trade on a species-specific
basis. 相似文献
82.
83.
Patricia A. Lampe Ellen B. Cornbrooks Anna Juhasz Eugene M. Johnson James L. Franklin 《Developmental neurobiology》1995,26(2):205-212
Rat sympathetic neurons undergo programmed cell death (PCD) in vitro and in vivo when they are deprived of nerve growth factor (NGF). Chronic depolarization of these neurons in cell culture with elevated concentrations of extracellular potassium ([K+]o) prevents this death. The effect of prolonged depolarization on neuronal survival is thought to be mediated by a rise of intracellular calcium concentration ([Ca2+]i) caused by Ca2+ influx through voltage-gated channels. In this report we investigate the effects of chronic treatment of rat sympathetic neurons with thapsigargin, an inhibitor of intracellular Ca2+ sequestration. In medium containing a normal concentration of extracellular Ca2+ ([Ca2+]o), thapsigargin caused a sustained rise of intracellular Ca2+ concentration and partially blocked death of NGF-deprived cells. Elevating [Ca2+]o in the presence of thapsigargin further increased [Ca2+]i, suggesting that the sustained rise of [Ca2+]i was caused by a thapsigargin-induced Ca2+ influx. This treatment potentiated the effect of thapsigargin on survival. The dihydropyridine Ca2+ channel antagonist, nifedipine, blocked both a sustained elevation of [Ca2+]i and enhanced survival caused by depolarization with elevated [K+]o, suggesting that these effects are mediated by Ca2+ influx through L-type channels. Nifedipine did not block the sustained rise of [Ca2+]i or enhanced survival caused by thapsigargin treatment, indicating that these effects were not mediated by influx of Ca2+ through L-type channels. These results provide additional evidence that increased [Ca2+]i can suppress neuronal PCD and identify a novel method for chronically raising neuronal [Ca2+]i for investigation of this and other Ca2+-dependent phenomena. © 1995 John Wiley & Sons, Inc. 相似文献
84.
Costa R Gomes NC Krögerrecklenfort E Opelt K Berg G Smalla K 《Environmental microbiology》2007,9(9):2260-2273
The Pseudomonas community structure and antagonistic potential in the rhizospheres of strawberry and oilseed rape (host plants of the fungal phytopathogen Verticillium dahliae) were assessed. The use of a new PCR-DGGE system, designed to target Pseudomonas-specific gacA gene fragments in environmental DNA, circumvented common biases of 16S rRNA gene-based DGGE analyses and proved to be a reliable tool to unravel the diversity of uncultured Pseudomonas in bulk and rhizosphere soils. Pseudomonas-specific gacA fingerprints of total-community (TC) rhizosphere DNA were surprisingly diverse, plant-specific and differed markedly from those of the corresponding bulk soils. By combining multiple culture-dependent and independent surveys, a group of Pseudomonas isolates antagonistic towards V. dahliae was shown to be genotypically conserved, to carry the phlD biosynthetic locus (involved in the biosynthesis of 2,4-diacetylphloroglucinol - 2,4-DAPG), and to correspond to a dominant and highly frequent Pseudomonas population in the rhizosphere of field-grown strawberries planted at three sites in Germany which have different land use histories. This population belongs to the Pseudomonas fluorescens phylogenetic lineage and showed closest relatedness to P. fluorescens strain F113 (97% gacA gene sequence identity in 492-bp sequences), a biocontrol agent and 2,4-DAPG producer. Partial gacA gene sequences derived from isolates, clones of the strawberry rhizosphere and DGGE bands retrieved in this study represent previously undescribed Pseudomonas gacA gene clusters as revealed by phylogenetic analysis. 相似文献
85.
86.
Dirkx E Schwenk RW Coumans WA Hoebers N Angin Y Viollet B Bonen A van Eys GJ Glatz JF Luiken JJ 《The Journal of biological chemistry》2012,287(8):5871-5881
Increased contraction enhances substrate uptake into cardiomyocytes via translocation of the glucose transporter GLUT4 and the long chain fatty acid (LCFA) transporter CD36 from intracellular stores to the sarcolemma. Additionally, contraction activates the signaling enzymes AMP-activated protein kinase (AMPK) and protein kinase D1 (PKD1). Although AMPK has been implicated in contraction-induced GLUT4 and CD36 translocation in cardiomyocytes, the precise role of PKD1 in these processes is not known. To study this, we triggered contractions in cardiomyocytes by electric field stimulation (EFS). First, the role of PKD1 in GLUT4 and CD36 translocation was defined. In PKD1 siRNA-treated cardiomyocytes as well as cardiomyocytes from PKD1 knock-out mice, EFS-induced translocation of GLUT4, but not CD36, was abolished. In AMPK siRNA-treated cardiomyocytes and cardiomyocytes from AMPKα2 knock-out mice, both GLUT4 and CD36 translocation were abrogated. Hence, unlike AMPK, PKD1 is selectively involved in glucose uptake. Second, we analyzed upstream factors in PKD1 activation. Cardiomyocyte contractions enhanced reactive oxygen species (ROS) production. Using ROS scavengers, we found that PKD1 signaling and glucose uptake are more sensitive to changes in intracellular ROS than AMPK signaling or LCFA uptake. Furthermore, silencing of death-activated protein kinase (DAPK) abrogated EFS-induced GLUT4 but not CD36 translocation. Finally, possible links between PKD1 and AMPK signaling were investigated. PKD1 silencing did not affect AMPK activation. Reciprocally, AMPK silencing did not alter PKD1 activation. In conclusion, we present a novel contraction-induced ROS-DAPK-PKD1 pathway in cardiomyocytes. This pathway is activated separately from AMPK and mediates GLUT4 translocation/glucose uptake, but not CD36 translocation/LCFA uptake. 相似文献
87.
88.
Francesca Megiorni Giovanni Luca Gravina Simona Camero Simona Ceccarelli Andrea Del Fattore Vincenzo Desiderio Federica Papaccio Heather P. McDowell Rajeev Shukla Antonio Pizzuti Filip Beirinckx Philippe Pujuguet Laurent Saniere Ellen Van der Aar Roberto Maggio Francesca De Felice Cinzia Marchese Carlo Dominici Vincenzo Tombolini Claudio Festuccia Francesco Marampon 《Journal of hematology & oncology》2017,10(1):161
Background
EPH (erythropoietin-producing hepatocellular) receptors are clinically relevant targets in several malignancies. This report describes the effects of GLPG1790, a new potent pan-EPH inhibitor, in human embryonal rhabdomyosarcoma (ERMS) cell lines.Methods
EPH-A2 and Ephrin-A1 mRNA expression was quantified by real-time PCR in 14 ERMS tumour samples and in normal skeletal muscle (NSM). GLPG1790 effects were tested in RD and TE671 cell lines, two in vitro models of ERMS, by performing flow cytometry analysis, Western blotting and immunofluorescence experiments. RNA interfering experiments were performed to assess the role of specific EPH receptors. Radiations were delivered using an x-6 MV photon linear accelerator. GLPG1790 (30 mg/kg) in vivo activity alone or in combination with irradiation (2 Gy) was determined in murine xenografts.Results
Our study showed, for the first time, a significant upregulation of EPH-A2 receptor and Ephrin-A1 ligand in ERMS primary biopsies in comparison to NSM. GLPG1790 in vitro induced G1-growth arrest as demonstrated by Rb, Cyclin A and Cyclin B1 decrease, as well as by p21 and p27 increment. GLPG1790 reduced migratory capacity and clonogenic potential of ERMS cells, prevented rhabdosphere formation and downregulated CD133, CXCR4 and Nanog stem cell markers. Drug treatment committed ERMS cells towards skeletal muscle differentiation by inducing a myogenic-like phenotype and increasing MYOD1, Myogenin and MyHC levels. Furthermore, GLPG1790 significantly radiosensitized ERMS cells by impairing the DNA double-strand break repair pathway. Silencing of both EPH-A2 and EPH-B2, two receptors preferentially targeted by GLPG1790, closely matched the effects of the EPH pharmacological inhibition. GLPG1790 and radiation combined treatments reduced tumour mass by 83% in mouse TE671 xenografts.Conclusions
Taken together, our data suggest that altered EPH signalling plays a key role in ERMS development and that its pharmacological inhibition might represent a potential therapeutic strategy to impair stemness and to rescue myogenic program in ERMS cells.89.
Gerlach NM McGlothlin JW Parker PG Ketterson ED 《Proceedings. Biological sciences / The Royal Society》2012,279(1730):860-866
In many species, each female pairs with a single male for the purpose of rearing offspring, but may also engage in extra-pair copulations. Despite the prevalence of such promiscuity, whether and how multiple mating benefits females remains an open question. Multiple mating is typically thought to be favoured primarily through indirect benefits (i.e. heritable effects on the fitness of offspring). This prediction has been repeatedly tested in a variety of species, but the evidence has been equivocal, perhaps because such studies have focused on pre-reproductive survival rather than lifetime fitness of offspring. Here, we show that in a songbird, the dark-eyed junco (Junco hyemalis), both male and female offspring produced by extra-pair fertilizations have higher lifetime reproductive success than do offspring sired within the social pair. Furthermore, adult male offspring sired via extra-pair matings are more likely to sire extra-pair offspring (EPO) themselves, suggesting that fitness benefits to males accrue primarily through enhanced mating success. By contrast, female EPO benefited primarily through enhanced fecundity. Our results provide strong support for the hypothesis that the evolution of extra-pair mating by females is favoured by indirect benefits and shows that such benefits accrue much later in the offspring's life than previously documented. 相似文献
90.
Maathuis EM Henderson RD Drenthen J Hutchinson NM Daube JR Blok JH Visser GH 《Journal of brachial plexus and peripheral nerve injury》2012,7(1):4-7