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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Introdução da truta arco-íris (Oncorhynchus mykiss) e suas conseqüências para a comunidade aquática dos rios de altitude do sul do Brasil

Sosinski, Lilian Terezinha Winckler January 2004 (has links)
A introdução de espécies exóticas é uma prática que acompanha a história da humanidade, sendo as espécies introduzidas a base da nutrição e economia em vários países. Porém, esse processo contínuo tem levado a uma homogeneização da flora e fauna global. Os ecossistemas aquáticos, que têm recebido menor atenção que os terrestres, têm sofrido perda de diversidade, hibridação, introdução de patógenos, degradação do habitat além da necessidade e alto custo de controle das espécies introduzidas. O desenvolvimento da aqüicultura tem acelerado a introdução de peixes exóticos, que são a base dessa produção em países como o Brasil. Além desta, entre as razões para a introdução citam-se o esporte, a manipulação ecológica com controle de organismos indesejáveis, o melhoramento dos estoques, a ornamentação ou ainda introduções acidentais. No Rio Grande do Sul, nos rios dos Campos de Cima da Serra estão ocorrendo introduções da espécie exótica truta arco- íris (Oncorhynchus mykiss) desde meados da década de 90 como forma de estímulo ao turismo rural. O objetivo dessa prática é a pesca esportiva, que atrai turistas de várias regiões. Porém, os rios da região possuem várias espécies de peixes endêmicas e as conseqüências dessa prática sobre a biota aquática são desconhecidas. O objetivo do presente trabalho é avaliar o efeito da introdução da truta arco-íris sobre o ecossistema de rios de baixa ordem no município de São José dos Ausentes – RS, Brasil. Para tanto foi descrita a biologia da truta arco- íris no novo ambiente, verificando sua alimentação, movimentação, presença e viabilidade da reprodução. A ictiofauna autóctone dos rios com ausência e presença de trutas foi comparada, bem como o efeito da predação sobre a macrofauna bentônica. A ictiofauna foi amostrada com o uso da pesca elétrica, sendo o conteúdo estomacal das trutas avaliado sazonalmente. Três trutas foram marcadas e acompanhadas por ii biotelemetria para determinação da sua área de vida. Um experimento com ninhos artificiais foi conduzido para verificação da sobrevivência de ovos de trutas nas condições dos rios de São José dos Ausentes. O experimento de exclusão de peixes foi feito a fim de avaliar o efeito da predação sobre a macrofauna bentônica, comparando a macrofauna em rios com e sem trutas. Os resultados indicaram que a truta arco- íris tem como alimento principal os invertebrados bentônicos, porém as maiores classes de tamanho incluem peixes em seus alimentos principais. Logo após sua introdução a movimentação é restrita, porém alguns exemplares foram capturados em um rio onde não foi feita introdução dessa espécie. Apesar de baixa, a sobrevivência dos adultos ocorre, assim como a reprodução. A sobrevivência dos ovos também é baixa, porém, uma pós-larva foi encontrada. A ictiofauna autóctone é diferenciada nos rios com presença de truta, apresentando menor riqueza e diversidade e uma tendência a diminuição da biomassa. A macrofauna bentônica também é diferenciada, apesar de não ser possível atribuir essa diferença somente à presença das trutas. / The introduction of exotic species is a practice that accompanies the humanity's history, being the introduced species the base of the nutrition and economy in several countries. Even so, that continuous process has been taking to a homogenization of the global flora and fauna. The aquatic ecosystems, that have been receiving smaller attention than the terrestrial ones, have been suffering diversity loss, hybridization, pathogens introduction, degradation of the habitat and costs of control of the introduced species. The development of aquaculture has been accelerating the introduction of exotic fish, that are the base of that production in countries as Brazil. Among the reasons for the introduction are the sporting fishing, the ecological manipulation with control of undesirable organisms, the improvement of the stocks, the ornamentation or still accidental introductions. In Rio Grande do Sul, in the rivers of Campos de Cima da Serra are occurring introductions of the species exotic rainbow trout (Oncorhynchus mykiss) from middles of the decade of 90 as incentive form to the rural tourism. The objective of that practice is the sporting fishing, which attracts tourists of several areas. Even so, the rivers of the area possess several endemic species of fish and the consequences of that practice on the aquatic biota have been ignored. The objective of the present work is to evaluate the effect of the introduction of the rainbow trout on rivers of low order in the municipal district of São José dos Ausentes - RS, Brazil. Thus the biology of the rainbow trout was described in the new environment, verifying its feeding, movement, presence and viability of reproduction. The autochthonous ictiofauna of the rivers with absence and presence of trouts was compared, as well as the effect of the predation on the benthic macrofauna. The ictiofauna was collected with the use of the electric fishing, being the stomacal content of the trouts evaluated seasonally. Three trouts were marked and accompanied by biotelemetry for determination of its life iv area. An experiment with artificial nests was driven for verification of the survival of eggs of trouts in the conditions of the rivers of São José dos Ausentes. The experiment of exclusion of fish was made in order to evaluate the effect of the predation on the benthic macrofauna, comparing the macrofauna in rivers with and without trouts. The results indicated that the rainbow trout has as main food benthic invertebrates, even so, in larger size classes it include fishes as main food. After its introduction the movement is restricted, even so trout s were found in a river where they were not introduced. Although low, have survival, as well as reproduction. The survival of the eggs is low, but it is happening in Silveira River, a post larvae being found. The autochthonous ictiofauna is differentiated in the rivers with trout presence, presenting smaller richness and diversity. The benthic macrofauna is also differentiated, in spite of not being possible to attribute that difference only to the presence of trouts.
92

Introdução da truta arco-íris (Oncorhynchus mykiss) e suas conseqüências para a comunidade aquática dos rios de altitude do sul do Brasil

Sosinski, Lilian Terezinha Winckler January 2004 (has links)
A introdução de espécies exóticas é uma prática que acompanha a história da humanidade, sendo as espécies introduzidas a base da nutrição e economia em vários países. Porém, esse processo contínuo tem levado a uma homogeneização da flora e fauna global. Os ecossistemas aquáticos, que têm recebido menor atenção que os terrestres, têm sofrido perda de diversidade, hibridação, introdução de patógenos, degradação do habitat além da necessidade e alto custo de controle das espécies introduzidas. O desenvolvimento da aqüicultura tem acelerado a introdução de peixes exóticos, que são a base dessa produção em países como o Brasil. Além desta, entre as razões para a introdução citam-se o esporte, a manipulação ecológica com controle de organismos indesejáveis, o melhoramento dos estoques, a ornamentação ou ainda introduções acidentais. No Rio Grande do Sul, nos rios dos Campos de Cima da Serra estão ocorrendo introduções da espécie exótica truta arco- íris (Oncorhynchus mykiss) desde meados da década de 90 como forma de estímulo ao turismo rural. O objetivo dessa prática é a pesca esportiva, que atrai turistas de várias regiões. Porém, os rios da região possuem várias espécies de peixes endêmicas e as conseqüências dessa prática sobre a biota aquática são desconhecidas. O objetivo do presente trabalho é avaliar o efeito da introdução da truta arco-íris sobre o ecossistema de rios de baixa ordem no município de São José dos Ausentes – RS, Brasil. Para tanto foi descrita a biologia da truta arco- íris no novo ambiente, verificando sua alimentação, movimentação, presença e viabilidade da reprodução. A ictiofauna autóctone dos rios com ausência e presença de trutas foi comparada, bem como o efeito da predação sobre a macrofauna bentônica. A ictiofauna foi amostrada com o uso da pesca elétrica, sendo o conteúdo estomacal das trutas avaliado sazonalmente. Três trutas foram marcadas e acompanhadas por ii biotelemetria para determinação da sua área de vida. Um experimento com ninhos artificiais foi conduzido para verificação da sobrevivência de ovos de trutas nas condições dos rios de São José dos Ausentes. O experimento de exclusão de peixes foi feito a fim de avaliar o efeito da predação sobre a macrofauna bentônica, comparando a macrofauna em rios com e sem trutas. Os resultados indicaram que a truta arco- íris tem como alimento principal os invertebrados bentônicos, porém as maiores classes de tamanho incluem peixes em seus alimentos principais. Logo após sua introdução a movimentação é restrita, porém alguns exemplares foram capturados em um rio onde não foi feita introdução dessa espécie. Apesar de baixa, a sobrevivência dos adultos ocorre, assim como a reprodução. A sobrevivência dos ovos também é baixa, porém, uma pós-larva foi encontrada. A ictiofauna autóctone é diferenciada nos rios com presença de truta, apresentando menor riqueza e diversidade e uma tendência a diminuição da biomassa. A macrofauna bentônica também é diferenciada, apesar de não ser possível atribuir essa diferença somente à presença das trutas. / The introduction of exotic species is a practice that accompanies the humanity's history, being the introduced species the base of the nutrition and economy in several countries. Even so, that continuous process has been taking to a homogenization of the global flora and fauna. The aquatic ecosystems, that have been receiving smaller attention than the terrestrial ones, have been suffering diversity loss, hybridization, pathogens introduction, degradation of the habitat and costs of control of the introduced species. The development of aquaculture has been accelerating the introduction of exotic fish, that are the base of that production in countries as Brazil. Among the reasons for the introduction are the sporting fishing, the ecological manipulation with control of undesirable organisms, the improvement of the stocks, the ornamentation or still accidental introductions. In Rio Grande do Sul, in the rivers of Campos de Cima da Serra are occurring introductions of the species exotic rainbow trout (Oncorhynchus mykiss) from middles of the decade of 90 as incentive form to the rural tourism. The objective of that practice is the sporting fishing, which attracts tourists of several areas. Even so, the rivers of the area possess several endemic species of fish and the consequences of that practice on the aquatic biota have been ignored. The objective of the present work is to evaluate the effect of the introduction of the rainbow trout on rivers of low order in the municipal district of São José dos Ausentes - RS, Brazil. Thus the biology of the rainbow trout was described in the new environment, verifying its feeding, movement, presence and viability of reproduction. The autochthonous ictiofauna of the rivers with absence and presence of trouts was compared, as well as the effect of the predation on the benthic macrofauna. The ictiofauna was collected with the use of the electric fishing, being the stomacal content of the trouts evaluated seasonally. Three trouts were marked and accompanied by biotelemetry for determination of its life iv area. An experiment with artificial nests was driven for verification of the survival of eggs of trouts in the conditions of the rivers of São José dos Ausentes. The experiment of exclusion of fish was made in order to evaluate the effect of the predation on the benthic macrofauna, comparing the macrofauna in rivers with and without trouts. The results indicated that the rainbow trout has as main food benthic invertebrates, even so, in larger size classes it include fishes as main food. After its introduction the movement is restricted, even so trout s were found in a river where they were not introduced. Although low, have survival, as well as reproduction. The survival of the eggs is low, but it is happening in Silveira River, a post larvae being found. The autochthonous ictiofauna is differentiated in the rivers with trout presence, presenting smaller richness and diversity. The benthic macrofauna is also differentiated, in spite of not being possible to attribute that difference only to the presence of trouts.
93

Effects of Hypoxia and Exercise on In Vivo Lactate Kinetics and Expression of Monocarboxylate Transporters in Rainbow Trout

Omlin, Teye D. January 2014 (has links)
The current understanding of lactate metabolism in fish is based almost entirely on interpretation of concentration measurements that cannot be used to infer changes in flux. Moreover, the transporters regulating these fluxes have never been characterized in rainbow trout. My goals were: (1) to quantify lactate fluxes in rainbow trout under normoxic resting conditions, during acute hypoxia, and exercise by continuous infusion of [U-14C] lactate; (2) to determine lactate uptake capacity of trout tissues by infusing exogenous lactate in fish rest and during graded exercise, and (3) to clone monocarboxylate transporters (MCTs) and determine the effects of exhausting exercise on their expression. Such information could prove important to understand the mechanisms underlying the classic “lactate retention” seen in trout white muscle after intense exercise. In normoxic resting fish, the rates of appearance (Ra) and disappearance (Rd) of lactate were always matched (~18 to 13 µmol kg-1 min-1), thereby maintaining a low baseline blood lactate concentration (~0.8 mM). In hypoxic fish, Ra lactate increased from baseline to 36.5 µmol kg-1 min-1, and was accompanied by an unexpected 52% increase in Rd reaching 30.3 µmol kg-1 min-1, accounting for a rise in blood lactate to 8.9 mM. In exercising fish, lactate flux was stimulated > 2.4 body lengths per second (BL s-1). As the fish reached critical swimming speed (Ucrit), Ra lactate was more stimulated (+67% to 40.4 μmol kg-1 min-1) than Rd (+41% to 34.7 μmol kg-1 min-1), causing an increase in blood lactate to 5.1mM. Fish infused with exogenous lactate stimulated Rd lactate by 300% (14 to 56 μmol kg-1 min-1) during graded exercise, whereas the Rd in resting fish increased by only 90% (21 to 40 µmol kg-1 min-1). Four MCT isoforms were partially cloned and characterized in rainbow trout: MCT1b was the most abundant in heart, and red muscle, but poorly expressed in gill and brain where MCT1a and MCT2 were prevalent. MCT4 was more expressed in the heart. Transcript levels of MCT2 (+260%; brain), MCT1a (+90%; heart) and MCT1b (+50%; heart) were stimulated by exhausting exercise. This study shows that: (i) the increase in Rd lactate plays a strategic role in reducing the lactate load imposed on the circulation. Without this response, blood lactate accumulation would double; (ii) a high capacity for lactate disposal in rainbow trout tissues is elicited by the increased blood-to-tissue lactate gradient when extra lactate is administered; and (iii) rainbow trout may be unable to release large lactate loads rapidly from white muscle after exhausting exercise (lactate retention) because they poorly express MCT4 in white muscle and fail to upregulate its expression during exercise.
94

THE BIOLOGICAL CONSEQUENCES OF CRYPTIC LOCAL ADAPTATION AND CONTEMPORARY EVOLUTION

Morgan M Sparks (15353425) 25 April 2023 (has links)
<p>  </p> <p>Evolution is the foundation for all of biology. However, our approaches and understanding of evolution—simply, the change of allele frequencies from one generation to the next—have themselves evolved over time. In this dissertation I explore multiple approaches to understand evolution and the consequences of evolution across variable scales and study organisms. First, I use meta-analytic techniques and Bayesian hierarchical models to investigate the phenotypic consequences of two forms of cryptic local adaptation, co- and countergradient variation, by leveraging a decades-old quantitative genetics approach (Chapter 1). I find large effects for both co- and countergradient variation, however they are obscured in natural settings by concurrent large environmental effects. I also show that these large effects are ubiquitous across phenotypic traits, organisms, and environmental gradients, suggesting that while similar phenotypes may be the evolutionary end point, the mechanisms to achieve those phenotypes likely vary. In the following chapter I explore the rapid evolution of a unique and understudied species introduction, pink salmon (<em>Oncorhynchus gorbuscha</em>) in the Great Lakes. Pink salmon were introduced into Lake Superior in a single introduction event and have broken two obligate life histories, anadromy (though they treat the Great Lakes like surrogate oceans) and their fixed two-year life cycle, making them ripe subjects for contemporary evolution. Using whole-genome sequence data, I first investigate the effects of a genetic drift in the form of a bottleneck at introduction and characterize the subsequent loss of genetic diversity (Chapter 2). I show that despite a large loss of genetic diversity, pink salmon also rapidly adapted to their novel environment based on signals of putative selection across numerous regions of the genome, particularly in a period gene associated with their daily circadian clock (<em>per2</em>). Next, I explore how genome structure likely aided adaptation by pink salmon to the Great Lakes, providing evidence that a supergene (~29 Mbp) containing an inversion on chromosome 10 swept to near fixation in the Great Lakes (Chapter 3) and likely aided in osmoregulatory adaptation to this novel environment. Finally, I end with a short perspective chapter (Chapter 4) where I highlight potential future research directions for each of the previous chapters. Together, this research investigates the drivers and consequences of evolution across multiple scales and shows the powerful effect of genetic drift and genetic adaptation in shaping the genomic and phenotypic attributes of populations.</p>
95

Dieldrin Induces Cytosolic [3H]7, 12-Dimethylbenz[a]Anthracene Binding but Not Multidrug Resistance Proteins in Rainbow Trout Liver

Curtis, L. R., Hemmer, M. J., Courtney, L A. 01 June 2000 (has links)
Previously it was demonstrated that biliary excretion of a single dose of [14C]dieldrin or [3H]7, 12-dimethylbenz/alanthracene (DMBA) was stimulated up to 700% and 300%, respectively, in rainbow trout fed 0.3-0.4 mg dieldrin/kg/d for 9-12 wk. This was not explained by increased activities of hepatic microsomal xenobiotic-metabolizing enzymes or increased amounts of any of six cytochrome P-450 isozymes quantitated by Western blots. It was hypothesized that stimulated excretion was explained by induction of (1) cytosolic binding proteins that facilitated intracellular trafficking of DMBA to sites of metabolism, or (2) ATP-dependent proteins that transport xenobiotic metabolites from liver to bile. Binding of 15 and 60 nmol [3H]DMBA/mg protein increased about 200% in hepatic cytosol from dieldrin-fed fish. A 50-fold molar excess of unlabeled DMBA reduced binding of 15 nmol [3H]DMBA/mg protein (nonspecific binding) by the same amount in cytosol from control and dieldrin-fed fish, indicating that dieldrin induced specific binding. Liver sections from control and dieldrin-fed fish were treated with multidrug resistance (MDR) protein monoclonal antibodies C494, C219, and JSB-1, and polyclonal antibody MDR Ab-1. There were no marked differences in optical densities of immunohistochemical staining near bile canaliculi of control and dieldrin-fed fish. Induction of xenobiotic binding capacity in cytosol of dieldrin-fed rainbow trout at least partially explained altered DMBA disposition in fish pretreated with this cyclodiene insecticide.
96

Anwendung des Comet Assay (Einzelzell-Gelelektrophorese) an Zellen von Fischen zum Nachweis gentoxischer Wirkungen im aquatischen Biomonitoring

Nehls, Sebastian 14 October 2013 (has links)
Gewässer sind Lebensgrundlage, jedoch gleichzeitig Schadstoffsenken für eine Vielzahl von Kontaminanten. Biologische Wirkungstests und das Biomonitoring aquatischer Proben sind daher besonders wichtig, um Umwelt-Gefahrenpotenziale erkennen zu können. Der "Comet Assay" (Einzelzell-Gelelektrophorese) ist ein Indikator von DNA-Strangbrüchen und wurde hier als Test auf gentoxische Wirkungen erprobt und angewandt. Mit bekannten, gentoxischen Substanzen wurden Nachweisgrenzen und Dosis-Wirkungs-Beziehungen für die Zelllinien RTG-2 und RTL-W1 (aus der Regenbogenforelle, Oncorhynchus mykiss) in vitro ermittelt und methodische Parameter an die Zellen angepasst. Der Test reagierte sehr sensitiv auf 4-Nitrochinolin-1-oxid. Die Substanz war daher geeignet, um in weiteren Versuchen als Positivkontrolle zu dienen. Zur Bewertung der Messdaten wurde ein geeignetes statistisches Verfahren gefunden, das auch historische Kontrollen mit einbezog. Der zeitliche Verlauf der DNA-Schädigung des Testsystems mit RTG-2-Zellen wurde ermittelt, und durch Inhibition der DNA-Reparatur mit Aphidicolin wurden Zusammenhänge zwischen der Entstehung von DNA-Strangbrüchen, der DNA-Reparaturkapazität sowie der Metabolisierungskapazität untersucht. In einer zweiten Phase wurden unbehandelte Wasserproben aus Rhein, Elbe sowie weitere Oberflächenwasserproben mit dem Comet Assay an RTG-2-Zellen getestet. Bei 15 von 49 Proben zeigten sich gentoxische Effekte. In einer dritten Phase wurden Erythrozyten von freilebenden Döbeln, Leuciscus cephalus, aus der Mosel mit dem Comet Assay untersucht. Die Fische von drei Messstellen zeigten erhöhte Werte von DNA-Schädigungen, gegenüber einer vierten, stromabwärts gelegenen Messstation. Korrelationen mit den Ergebnissen zusätzlicher Biomarker ergaben sich nur teilweise. Chemische Analysen von Wasser- oder Gewebeproben ließen keine Rückschlüsse auf verursachende Kontaminanten zu - gerade dies unterstreicht jedoch die Wichtigkeit biologischer Tests bei komplexen Proben. / Bodies of Water are both vital resources and pollutant sinks for a multitude of contaminants. Therefore, biological effect tests and biomonitoring of aquatic samples are of particular importance to detect potential environmental hazards. The "comet assay" (single cell gel electrophoresis) is an indicator for DNA strand breaks and was explored and applied as a genotoxicity test in the present study. Known genotoxic substances were used to determine the detection limits and dose-response relationships for the cell lines RTG-2 and RTL-W1 (from rainbow trout, Oncorhynchus mykiss) in vitro, and to adapt methodological parameters to the cells. The test was very sensitive to 4-Nitroquinoline-1-oxide. This substance was therefore well-suited to serve as positive control in further experiments. In order to evaluate the measurement data, an appropriate statistical procedure was developed, which also took "historical" controls into account. The time course of DNA damage in the test system using RTG-2 cells was determined, and relationships between the origin of DNA strand breaks, DNA repair capacity and the metabolizing capacity of the cells was investigated by means of inhibition of DNA repair with Aphidicoline. In the second stage, native water samples from the rivers Rhine and Elbe and further surface waters were tested with the comet assay, using RTG-2 cells. 15 out of 49 samples showed genotoxic effects. In a third stage, erythrocytes of feral chub, Leuciscus cephalus, from the Moselle river were examined with the comet assay. The fish from three measuring stations showed elevated values of DNA damage compared to fish sampled from a downstream station. There were only partly correlations with the results from additional biomarkers. Chemical analyses of water and tissue samples did not permit conclusions on effect-causing substances.However, this emphasizes the importance of biological tests in dealing with complex environmental samples.
97

Climate warming effects on the life cycle of the parasite Ceratomyxa shasta in salmon of the Pacific Northwest

Chiaramonte, Luciano V. 08 March 2013 (has links)
Aquatic ecosystems continue to be increasingly affected by climate warming. For salmonids in the Pacific Northwest of North America, increasing temperatures pose tighter thermal constraints on their habitat use as well as aspects of their individual performance, such as disease resistance. This thesis examines the effect of temperature on the phenology of the Ceratomyxa shasta life cycle, the effect of thermal refugia on disease risk in juvenile salmonids in the Klamath River, CA, and the spatial and temporal distribution of C. shasta in the Willamette River, OR. We developed a biological model that predicts an acceleration of the C. shasta life cycle development due to climate shifts in the Klamath River, resulting in more generations per year and earlier seasonal parasite occurrence. We showed that in early summer the Beaver Creek-Klamath River confluence provides juvenile Chinook and coho salmon an area of lower parasite doses and cooler temperatures than the main stem, thus lessening disease risk. By accelerating the development of C. shasta in its hosts, increasing temperatures will result in earlier parasite transmission to juvenile salmonids and a longer season of infectivity. These fish may find disease refuge at cold tributary inflows to the main stem of the Klamath River in early summer, further adding to the benefit of these important thermal habitats. To determine if similar disease patterns occur in other rivers with the parasite, we described spatial and temporal occurrence of C. shasta in the Willamette River. By collecting weekly water sampling at four sites over 28 months we characterize seasonal and annual differences of parasite abundance, which varies with weekly temperature. We also collected samples along the length of the main stem and its tributaries and identified spatial differences in C. shasta spore densities. Identification of spatial and temporal variation of C. shasta in the Willamette River provides a foundation for understanding future patterns of disease occurrence in this river where conservation of anadromous fisheries is also of concern. This thesis identifies likely responses of C. shasta to climate warming in the Klamath River, with useful application to other rivers in the Pacific Northwest. / Graduation date: 2013
98

Telomerase and its reverse transcriptase subunit TERT : identification and oestrogenic modulation of telomerase transcription in two aquatic test species - European Purple Sea Urchin (Paracentrotus Lividus) and Rainbow Trout (Oncorhynchus Mykiss)

Brannan, Katla Jorundsdottir January 2012 (has links)
A plethora of naturally-produced steroid hormones, or artificial homologues of them, are being introduced into the aquatic and terrestrial environments each year. Two examples of these are the natural oestrogen 17-oestradiol (E2) and the oestrogen receptor antagonist, Bisphenol A (BPA), both of which target the ribonucleoprotein telomerase through upregulation of its telomerase reverse transcriptase component, TERT. The main objectives of this study were firstly to isolate and characterize the actual mRNA sequence for the telomerase catalytic subuninit, Tert, in rainbow trout (Oncorhynchus mykiss) (Walbaum, 1792) and European purple sea urchin (Paracentrotus lividus) (Lamarck, 1816), with the aim of developing qPCR assays for the amplification and quantification of Tert. Further objectives were to use these assays in controlled exposure studies to establish whether and to what extent the aforementioned chemicals regulate Tert transcription and by doing so further understand the mechanism of Telomerase gene expression and the extent to which environmental oestrogen can interfere. The initial step of sequence characterization and assay devlopment was successful in the case of rainbow trout where two possible splice variants of Tert mRNA are identified, omTertShort and omTertLong. Two qPCR assays were developed for the relative quantification of both of these splice variants in rainbow trout samples, the latter of these successfully amplifying its target in test samples. In order to demonstrate in vitro and in vivo modulation of telomerase activity and mRNA expression, early life-stages of rainbow trout and purple sea urchin, as well as rainbow trout hepatocytes, were exposed to a range of concentrations of E2 and BPA. Purple sea urchin embryos were exposed to 200, 20 and 2 ng E2/ml for 28 hours until they had reached the stage of pluteus larvaes. Rainbow trout embryos were exposed to 500, 20 and 0.1 ng E2/ml and 600 and 150 ng BPA/ml for 167 days from immediately after fertilization. Rainbow trout hepatocytes were exposed to 20 and 2 ng E2/ml for 48 hours. The results from this study show that telomerase activity as well as TERT mRNA expression can be significantly modulated by exposure to oestrogens and other oestrogenic chemicals. E2 concentrations as low as 20 ng/ml lead to an increase in telomerase activity early-life stages of purple sea urchin and upregulation in the transcription of Tert mRNA in unhatched rainbow trout embryos. BPA induced similar response (600 ng/ml) in hatched rainbow trout alevins larvae. Very high exposures to E2 (500 ng/ml) do however lead to downregulation of Tert mRNA in hatched alevins larvae. Differential regulatory response can be observed between different tissue types of 167 day old fry, with an upregulatory response observed at 0.1 ng E2/ml in liver and muscle tissues, but not in brain. Similarly, brain tissues were observed expressing significantly less mRNA than liver and muscle samples when exposed to BPA (150 ng/ml). It is evident that the previously observed link between environmental oestrogens and telomerase is also present in the two test species examined; purple sea urchin and rainbow trout.
99

Citlivost adultních ryb různých druhů k anestetiku hřebíčkový olej / Sensitivity to anesthetic clove oil different species of adult fish

ŠKEŘÍK, Jindřich January 2007 (has links)
Nomenclature: Sensitivity to anesthetic clove oil different species of adult fish Sensitivity of breeding fishes of various species (Siberian sturgeon, Brook trout, Black carp- young breeding fishes) for anesthetic clove oil was probed by the tests performed at temperature in the period of stripping (apart from Brook trout and Black carp). The tests were carried out with 17 fish species- with cyprinids (Ide- golden form, Common dace, European Chub, Sneep, Barbel, Grass carp, Black carp, bighead carp), salmonids (Brown trout, Rainbow trout, Brook trout), thymallinae (Grayling), pikes (Northern pike), perches (Pike-perch), sturgeons (Siberian sturgeon, Beluga) and airbreathing catfishes (North African catfish). Using concentration of 0,03ml.l-1 (Brown trout, Rainbow trout, Brook trout, Grayling, Pike, Pike perch, Ide, Dace, Chub, Barbel and Sneep), 0,04ml.l-1 (Grass carp, Black carp, Bighead carp), 0,05ml.l-1 (North African catfish) and 0,07ml.l-1 (Siberian sturgeon, Beluga) the IIb. Phase has been achieved, which is sufficient for manipulation with fishes during stripping. The anesthesia subsided after time period of 10-17 minutes (12 species) at the majority of fishes and at others after interval of 20-26 minutes (5 species). The results confirmed concentrations recommended for salmodis and Grayling (0,025-0,03ml.l-1), sturgeons (0,07ml.l-1), and North African catfish (0,05ml.l-1). At the majority of cyprinids (apart from Grass carp, Black carp and Bighead carp), the concentration used was lower than recommended (0,04-0,05ml.l-1)
100

Rörelseaktivitet hos regnbågar (Oncorhynchus mykiss) med olika antal eumelaninfläckar, utsatta för stressande sportfiske / Locomotor activity of rainbow trout (Oncorhynchus mykiss) with different numbers of eumelanic skin spots, exposed to the stressor sport fishing

Gesslin, Enar January 2023 (has links)
Rainbow trout (Oncorhynchus mykiss) are introduced in large parts of the world and are commonly farmed for consumption as well as a valued sport fish. Many species of salmonids show large intraspecific variation in pigmentation, which has been shown to correlate with stress response and several other behavioral traits. In this study, the behavior and stress response of rainbow trout linked to pigmentation is investigated, depending on previous sport fishing experience. Through data from a previous study on rainbow trout in semi-natural ponds, locomotor activity was measured as a proxy of stress, under three different sport fishing treatments. From previous photos, the pigment spots of each rainbow trout are counted to test the correlation with locomotor activity. In addition, it is tested whether different previous experience of sport fishing means a higher stress response when re-exposed to fishing. No significant relationship between pigment spots and locomotor activity could be obtained for the three treatment groups. However, significant differences in locomotor activity due to angling experience between treatment groups upon re-exposure to fishing were found, with fish that were inexperienced in angling having higher locomotor activity compared to previously caught fish. Sport fishing and catch-and-release had the effect of reducing locomotor activity in rainbow trout, which can be interpreted as fishing could both stress them and trigger the fish's feeding response, depending on previous experience. Fishing is believed to create a passivation due to the negative association of being caught, while fish not previously caught were activated by sport fishing. The study's missing correlation between pigment spots and stress has been both confirmed and denied in other studies and may depend on the origin and the degree of domestication, which means that the correlation within other species of salmonids or fish with different origins would be relevant to investigate. / Regnbåge (Oncorhynchus mykiss) förekommer introducerade i stora delar av världen och är vanliga att odlas för konsumtion samt en uppskattad sportfisk. Många arter av salmonider visar stor intraspecifik variation i pigmentering, vilket visats korrelera med stressrespons och flera andra beteendemässiga karaktärsdrag. I denna studie undersöks regnbågarnas beteende och stressrespons kopplat till pigmentering, beroende på tidigare erfarenhet av sportfiske. Genom data från en tidigare studie på regnbåge i semi-naturliga dammar mäts rörelseaktivitet som indirektmått på stress, under tre olika sportfiskebehandlingar. Från tidigare foton räknas varje regnbåges pigmentfläckar för att testa korrelationen med rörelseaktivitet. Därtill testas om olika tidigare erfarenhet av sportfiske, innebär högre stressrespons vid återexponering för fiske. Inget signifikant samband mellan pigmentfläckar och rörelseaktivitet kunde erhållas för de tre behandlingsgrupperna. Signifikanta skillnader i rörelseaktivitet på grund av erfarenheten av sportfiske mellan behandlingsgrupperna vid återexponering för fiske fanns dock, där fisk som var oerfaren sportfiske hade högre rörelseaktivitet jämfört med fisk som fångats tidigare. Sportfiske och catch-and-release hade effekten att minska rörelseaktiviteten hos regnbågar, vilket kan tolkas som att fisket både kunde stressa och trigga fiskens födorespons, beroende på tidigare erfarenhet. Fisket tros skapa en passivisering på grund av den negativa associationen att bli fångad, medan fisk som inte fångats tidigare aktiverades av sportfisket. Studiens uteblivna samband mellan pigmentfläckar och stress har både bekräftats och dementerats i andra studier och kan bero på ursprung och graden av domesticering, vilket gör att sambandet inom andra arter av salmonider eller fisk med olika ursprung vore aktuellt att undersöka.

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