211. Seasonal variation in marine-snow-associated and ambient-water prokaryotic communities in the northern Adriatic SeaJana Vojvoda, Dominique Lamy, Eva Sintes, Juan A.L. Garcia, Valentina Turk, Gerhard J. Herndl, 2014, izvirni znanstveni članek Povzetek: The structure and activity of prokaryotic communities were determined in marine snow and in the ambient water of the northern Adriatic Sea in different seasons (autumn, spring and summer). The seasonal variation in the composition of marine-snow-associated and ambient-water bacterial communities was assessed by T-RFLP (Terminal Restriction Fragment Length Polymorphism) on the 16S rRNA gene (16S rDNA) and 16S rRNA transcript (16S rRNA) level. On the 16S rDNA level, the bacterial community composition of the marine snow and ambient water was similar in summer and autumn, but not in spring. In contrast, on the 16S rRNA level, indicative of the active bacterial community, the marine-snow-associated bacterial community was different from that of the ambient-water, and different from the bacterial community on the 16S rDNA level, except in autumn. To phylogenetically characterize the bacterial and archaeal community composition associated with marine snow and the ambient water, clone libraries of 16S rDNA and 16S rRNA were constructed from 2 contrasting seasons. Phylogenetic profiling revealed a higher similarity among bacterial communities in summer compared to late autumn. Certain bacterial and archaeal groups were exclusively associated with summer or autumn marine snow, suggesting that marine-snow-associated prokaryotic communities are subjected to successional changes similar to ambient-water communities. Moreover, the presence of bacterial groups enriched in marine snow including Vibrionales and sulphate-reducing bacteria is consistent with niche partitioning and metabolic adaptations of the particle-associated microbiota. Ključne besede: marine snow, free-living-bacteria, Northern Adriatic sea Objavljeno v DiRROS: 02.08.2024; Ogledov: 152; Prenosov: 96
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212. Expression analysis of all protease genes reveals cathepsin K to be overexpressed in glioblastomaUrška Verbovšek, Helena Motaln, Ana Rotter, Nadia A. Atai, Kristina Gruden, Cornelis J. F. van Noorden, Tamara Lah Turnšek, 2014, izvirni znanstveni članek Povzetek: Background
Cancer genome and transcriptome analyses advanced our understanding of cancer biology. We performed transcriptome analysis of all known genes of peptidases also called proteases and their endogenous inhibitors in glioblastoma multiforme (GBM), which is one of the most aggressive and deadly types of brain cancers, where unbalanced proteolysis is associated with tumor progression.
Methods
Comparisons were performed between the transcriptomics of primary GBM tumors and unmatched non-malignant brain tissue, and between GBM cell lines (U87-MG and U373) and a control human astrocyte cell line (NHA). Publicly-available data sets and our own datasets were integrated and normalized using bioinformatics tools to reveal protease and protease inhibitor genes with deregulated expression in both malignant versus non-malignant tissues and cells.
Results
Of the 311 protease genes identified to be differentially expressed in both GBM tissues and cells, 5 genes were highly overexpressed, 2 genes coding for non-peptidase homologues transferrin receptor (TFRC) and G protein-coupled receptor 56 (GPR56), as well as 3 genes coding for the proteases endoplasmic reticulum aminopeptidase 2 (ERAP2), glutamine-fructose-6-phosphate transaminase 2 (GFPT2) and cathepsin K (CTSK), whereas one gene, that of the serine protease carboxypeptidase E (CPE) was strongly reduced in expression. Seventy five protease inhibitor genes were differentially expressed, of which 3 genes were highly overexpressed, the genes coding for stefin B (CSTB), peptidase inhibitor 3 (PI3 also named elafin) and CD74. Seven out of 8 genes (except CSTB) were validated using RT-qPCR in GBM cell lines. CTSK overexpression was validated using RT-qPCR in GBM tissues as well. Cathepsin K immunohistochemical staining and western blotting showed that only proteolytically inactive proforms of cathepsin K were overexpressed in GBM tissues and cells.
Conclusions
The presence of high levels of inactive proforms of cathepsin K in GBM tissues and cells indicate that in GBM the proteolytic/collagenolytic role is not its primary function but it plays rather a different yet unknown role. Ključne besede: glioblastoma multiforme, genes Objavljeno v DiRROS: 02.08.2024; Ogledov: 239; Prenosov: 160
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213. The subgenual organ complex in the cave cricket Troglophilus neglectus (Orthoptera: Rhaphidophoridae) : comparative innervation and sensory evolutionJohannes Strauß, Nataša Stritih Peljhan, Reinhard Lakes-Harlan, 2014, izvirni znanstveni članek Povzetek: Comparative studies of the organization of nervous systems and sensory organs can reveal their evolution and specific adaptations. In the forelegs of some Ensifera (including crickets and tettigoniids), tympanal hearing organs are located in close proximity to the mechanosensitive subgenual organ (SGO). In the present study, the SGO complex in the non-hearing cave cricket Troglophilus neglectus (Rhaphidophoridae) is investigated for the neuronal innervation pattern and for organs homologous to the hearing organs in related taxa. We analyse the innervation pattern of the sensory organs (SGO and intermediate organ (IO)) and its variability between individuals. In T. neglectus, the IO consists of two major groups of closely associated sensilla with different positions. While the distal-most sensilla superficially resemble tettigoniid auditory sensilla in location and orientation, the sensory innervation does not show these two groups to be distinct organs. Though variability in the number of sensory nerve branches occurs, usually either organ is supplied by a single nerve branch. Hence, no sensory elements clearly homologous to the auditory organ are evident. In contrast to other non-hearing Ensifera, the cave cricket sensory structures are relatively simple, consistent with a plesiomorphic organization resembling sensory innervation in grasshoppers and stick insects. Ključne besede: neuroanatomy, chordotonal organ, mechanoreceptor, sensory innervation, neural phylogeny Objavljeno v DiRROS: 02.08.2024; Ogledov: 133; Prenosov: 146
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214. Potato Virus Y infection hinders potato defence response and renders plants more vulnerable to Colorado potato beetle attackMarko Petek, Ana Rotter, Polona Kogovšek, Špela Baebler, Axel Mithöfer, Kristina Gruden, 2014, izvirni znanstveni članek Povzetek: In the field, plants are challenged by more than one biotic stressor at the same time. In this study, the molecular interactions between potato (Solanum tuberosum L.), Colorado potato beetle (Leptinotarsa decemlineata Say; CPB) and Potato virus YNTN (PVYNTN) were investigated through analyses of gene expression in the potato leaves and the gut of the CPB larvae, and of the release of potato volatile compounds. CPB larval growth was enhanced when reared on secondary PVYNTN-infected plants, which was linked to decreased accumulation of transcripts associated with the antinutritional properties of potato. In PVYNTN-infected plants, ethylene signalling pathway induction and induction of auxin response transcription factors were attenuated, while no differences were observed in jasmonic acid (JA) signalling pathway. Similarly to rearing on virus-infected plants, CPB larvae gained more weight when reared on plants silenced in JA receptor gene (coi1). Although herbivore-induced defence mechanism is regulated predominantly by JA, response in coi1-silenced plants only partially corresponded to the one observed in PVYNTN-infected plants, confirming the role of other plant hormones in modulating this response. The release of β-barbatene and benzyl alcohol was different in healthy and PVYNTN-infected plants before CPB larvae infestation, implicating the importance of PVYNTN infection in plant communication with its environment. This was reflected in gene expression profiles of neighbouring plants showing different degree of defence response. This study thus contributes to our understanding of plant responses in agro-ecosystems. Ključne besede: insect midgut transcriptional response, gene expression, plant defence, volatile organic compounds, potato Objavljeno v DiRROS: 02.08.2024; Ogledov: 142; Prenosov: 113
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215. Involvement of potato (Solanum tuberosum L.) MKK6 in response to Potato virus YAna Lazar, Anna Coll Rius, David Dobnik, Špela Baebler, Apolonija Bedina Zavec, Jana Žel, Kristina Gruden, 2014, izvirni znanstveni članek Povzetek: Mitogen-activated protein kinase (MAPK) cascades have crucial roles in the regulation of plant development and in plant responses to stress. Plant recognition of pathogen-associated molecular patterns or pathogen-derived effector proteins has been shown to trigger activation of several MAPKs. This then controls defence responses, including synthesis and/or signalling of defence hormones and activation of defence related genes. The MAPK cascade genes are highly complex and interconnected, and thus the precise signalling mechanisms in specific plant%pathogen interactions are still not known. Here we investigated the MAPK signalling network involved in immune responses of potato (Solanum tuberosum L.) to Potato virus Y, an important potato pathogen worldwide. Sequence analysis was performed to identify the complete MAPK kinase (MKK) family in potato, and to identify those regulated in the hypersensitive resistance response to Potato virus Y infection. Arabidopsis has 10 MKK family members, of which we identified five in potato and tomato (Solanum lycopersicum L.), and eight in Nicotiana benthamiana. Among these, StMKK6 is the most strongly regulated gene in response to Potato virus Y. The salicylic acid treatment revealed that StMKK6 is regulated by the hormone that is in agreement with the salicylic acid-regulated domains found in the StMKK6 promoter. The involvement of StMKK6 in potato defence response was confirmed by localisation studies, where StMKK6 accumulated strongly only in Potato-virus-Y-infected plants, and predominantly in the cell nucleus. Using a yeast two-hybrid method, we identified three StMKK6 targets downstream in the MAPK cascade: StMAPK4_2, StMAPK6 and StMAPK13. These data together provide further insight into the StMKK6 signalling module and its involvement in plant defence. Ključne besede: plant diseases, potato, molecular biology Objavljeno v DiRROS: 02.08.2024; Ogledov: 137; Prenosov: 154
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216. The process of pair formation mediated by substrate-borne vibrationsin a small insectJernej Polajnar, Anna Eriksson, Marco Valerio Rossi Stacconi, Andrea Lucchi, Gianfranco Anfora, Meta Virant-Doberlet, Valerio Mazzoni, 2014, izvirni znanstveni članek Povzetek: The ability to identify and locate conspecifics depends on reliable transfer of information between emitter and receiver. For a majority of plant-dwelling insects communicating with substrate-borne vibrations, localization of a potential partner may be a difficult task due to their small body size and complex transmission properties of plants. In the present study, we used the leafhopper Scaphoideus titanus as a model to investigate duetting and mate searching associated with pair formation. Studying these insects on a natural substrate, we showed that the spatio-temporal structure of a vibrational duet and the perceived intensity of partner's signals influence the mating behaviour. Identification, localization and courtship stages were each characterized by a specific duet structure. In particular, the duet structure differed in synchronization between male and female pulses, which enables identification of the partner, while the switch between behavioural stages was associated with the male-perceived intensity of vibrational signals. This suggests that males obtain the information about their distance from the female and optimize their strategy accordingly. More broadly, our results show that even in insects smaller than 1 cm, vibrational signals provide reliable information needed to find a mating partner. Ključne besede: mating behaviour, identification, localization, courtship, vibrational communication Objavljeno v DiRROS: 02.08.2024; Ogledov: 156; Prenosov: 97
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217. Macrofauna associated with a bank of Cladocora caespitosa (Anthozoa, Scleractinia) in the Gulf of Trieste (northern Adriatic)Valentina Pitacco, Martina Orlando-Bonaca, Borut Mavrič, Lovrenc Lipej, 2014, izvirni znanstveni članek Povzetek: The Mediterranean stony coral Cladocora caespitosa (Linnaeus, 1767) is a native colonial, zooxanthellate, shallow water coral, particularly sensitive to global changes and anthropogenic activities. Due to its shape and size, it is able to host a diversifi ed faunal assemblage, which is still relatively unknown. A recently discovered bank of C. caespitosa, discovered close to Cape Ronek (Gulf of Trieste, Slovenia), was investigated in November 2010. Altogether 121 invertebrate taxa, belonging to 9 different phyla were found. Taxa composition in colonies differed markedly from the surrounding areas within the bank. Only 5 taxa (4 % of the total) were found both within and without C. caespitosa colonies. Our results confi rm the role of C. caespitosa as a habitat builder and indicate the importance of the studied bank for biodiversity Objavljeno v DiRROS: 02.08.2024; Ogledov: 129; Prenosov: 211
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218. Mixtures of Chemical Pollutants at European Legislation Safety Concentrations: How Safe are They?Raquel Negrão Carvalho, Augustine Aruqwe, Selim Ait-Aissa, Anne Bado-Nilles, Stefania Balzamo, Anders Baun, Shimshon Belkin, Ludek Blaha, Francois Brion, Daniela Conti, Vesna Flander-Putrle, Valentina Turk, 2014, izvirni znanstveni članek Povzetek: The risk posed by complex chemical mixtures in the environment to wildlife and humans is increasingly debated, but has been rarely tested under environmentally relevant scenarios. To address this issue, two mixtures of 14 or 19 substances of concern (pesticides, pharmaceuticals, heavy metals, polyaromatic hydrocarbons, a surfactant, and a plasticizer), each present at its safety limit concentration imposed by the European legislation, were prepared and tested for their toxic effects. The effects of the mixtures were assessed in 35 bioassays, based on 11 organisms representing different trophic levels. A consortium of 16 laboratories was involved in performing the bioassays. The mixtures elicited quantifiable toxic effects on some of the test systems employed, including i) changes in marine microbial composition, ii) microalgae toxicity, iii) immobilization in the crustacean Daphnia magna, iv) fish embryo toxicity, v) impaired frog embryo development, and vi) increased expression on oxidative stress-linked reporter genes. Estrogenic activity close to regulatory safety limit concentrations was uncovered by receptor-binding assays. The results highlight the need of precautionary actions on the assessment of chemical mixtures even in cases where individual toxicants are present at seemingly harmless concentrations. Ključne besede: morje, analizna kemija, biologija, evtrofikacija, hranilne snovi, fitoplankton, onesnaževanje, Piranski zaliv Objavljeno v DiRROS: 02.08.2024; Ogledov: 144; Prenosov: 183
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219. Loop-mediated isothermal amplification of specific endoglucanase gene sequence for detection of the bacterial wilt pathogen Ralstonia solanacearumRok Lenarčič, Dany Morisset, Manca Pirc, Pablo Llop, Maja Ravnikar, Tanja Dreo, 2014, izvirni znanstveni članek Povzetek: The increased globalization of crops production and processing industries also promotes the side-effects of more rapid and efficient spread of plant pathogens. To prevent the associated economic losses, and particularly those related to bacterial diseases where their management relies on removal of the infected material from production, simple, easy-to-perform, rapid and cost-effective tests are needed. Loop-mediated isothermal amplification (LAMP) assays that target 16S rRNA, fliC and egl genes were compared and evaluated as on-site applications. The assay with the best performance was that targeted to the egl gene, which shows high analytical specificity for diverse strains of the betaproteobacterium Ralstonia solanacearum, including its non-European and non-race 3 biovar 2 strains. The additional melting curve analysis provides confirmation of the test results. According to our extensive assessment, the egl LAMP assay requires minimum sample preparation (a few minutes of boiling) for the identification of pure cultures and ooze from symptomatic material, and it can also be used in a high-throughput format in the laboratory. This provides sensitive and reliable detection of R. solanacearum strains of different phylotypes. Ključne besede: plant pathogens, bacterial diseases Objavljeno v DiRROS: 02.08.2024; Ogledov: 152; Prenosov: 77
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220. Artificially induced migration of redox layers in a coastal sediment from the Northern AdriaticEduard Metzger, D. Langlet, E. Viollier, Neža Koron, Bettina Riedel, Michael Stachowitsch, Jadran Faganeli, M. Tharaud, E. Geslin, F. Jorissen, 2014, izvirni znanstveni članek Povzetek: Long-term experimental studies suggest that, under transient anoxic conditions, redox fronts within the sediment shift upwards, causing sequential rise and fall of benthic fluxes of reduced species (Mn(II), Fe(II) and S(-II)). Infaunal benthic organisms are associated with different redox fronts as micro-habitats and must be affected by such changes during natural hypoxia events. In order to document the geochemical evolution of the sediment during prolonged anoxia in the framework of an in situ experiment designed to mimic natural conditions, benthic chambers were deployed on the seafloor of the Northern Adriatic and sampled after 9, 30 and 315 days of incubation. Oxygen and sulfide were measured continuously in the early stages (9 days) of the experiment. High-resolution pore water profiles were sampled by DET probes and redox-sensitive species (S(VI), Mn(II) and Fe(II)) and alkalinity were measured.
Starting oxygen saturation was about 80% within the chamber. After 7 days, anoxia was established in the bottom waters within the chambers. Mn(II) and Fe(II) started diffusing towards the anoxic water column until they reached the surficial sediment. Being reoxidized there, Mn and Fe reprecipitated, giving a rusty coloration to the seafloor. Infaunal species appeared at the sediment surface. After 20 days, all macro-organisms were dead. Decomposition of macro-organisms at the sediment–water interface generated S(-II) within the entire height of the chamber, leading to a downward flux of sulfides into the sediment, where they were quickly oxidized by metallic oxides or precipitated as FeS. S(-II) was below detection in the water column and pore waters at the end of the experiment. Our results suggest that S(-II) enrichment in the water column of coastal systems, which are episodically anoxic, is strongly controlled by the biomass of benthic macrofauna and its decay during anoxia, whereas its residence time in the water column is controlled by iron availability (as solid oxides or as dissolved reduced cations) within the sediment, even without water circulation. Ključne besede: Adriatic Sea, marine sediments, anoxia, Northern Adriatic Objavljeno v DiRROS: 02.08.2024; Ogledov: 128; Prenosov: 146
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