Sirvi Autor "Kreitsberg, Randel" järgi
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Kirje Differences on the level of hepatic transcriptome between two flatfish species in response to liver cancer and environmental pollution levels(Elsevier, 2023) Sepp, Tuul; Baines, Ciara; Kreitsberg, Randel; Scharsack, Jörn Peter; Nogueira, Pedro; Lang, Thomas; Fort, Jérôme; Sild, Elin; Clarke, John T.; Tuvikene, Arvo; Meitern, RichardEnvironmental factors can cause cancer in both wild animals and humans. In ecological settings, genetic variation and natural selection can sometimes produce resilience to the negative impacts of environmental change. An increase in oncogenic substances in natural habitats has therefore, unintentionally, created opportunities for using polluted habitats to study cancer defence mechanisms. The Baltic and North Sea are among the most contaminated marine areas, with a long history of pollution. Two flatfish species (flounder, Platichthys flesus and dab, Limanda limanda) are used as ecotoxicological indicator species due to pollution-induced liver cancer. Cancer is more prevalent in dab, suggesting species-specific differences in vulnerability and/or defence mechanisms. We conducted gene expression analyses for 30 flatfishes. We characterize between- and within-species patterns in potential cancer-related mechanisms. By comparing cancerous and healthy fishes, and noncancerous fishes from clean and polluted sites, we suggest also genes and related physiological mechanisms that could contribute to a higher resistance to pollution-induced cancer in flounders. We discovered changes in transcriptome related to elevated pollutant metabolism, alongside greater tumour suppression mechanisms in the liver tissue of flounders compared to dabs. This suggests either hormetic upregulation of tumour suppression or a stronger natural selection pressure for higher cancer resistance for flounders in polluted environment. Based on gene expression patterns seen in cancerous and healthy fish, for liver cancer to develop in flounders, genetic defence mechanisms need to be suppressed, while in dabs, analogous process is weak or absent. We conclude that wild species could offer novel insights and ideas for understanding the nature and evolution of natural cancer defence mechanisms.Kirje Eesti rannikumere reostuse hindamine kalade bioloogiliste kahjustuste kaudu : aruanne(2016) Tuvikene, Arvo; Kreitsberg, Randel; Raig, Reelika; Tuvikene, Arvo (koostaja); Eesti Maaülikool. Põllumajandus- ja keskkonnainstituut. LimnoloogiakeskusTöö eesmärkideks oli: 1) testida HELCOMi poolt soovitatud vee reostuse tuumik- biomarkereid: a. polütsükliliste aromaatsete süsivesinike (PAH) laguproduktide kontsentratsiooni ahvena, räime ja lesta sapis/uriinis, b. kalade punaliblede kahjustuste alusel hinnata Eesti rannikumere geno- ja tsütotoksilisust 2) nende biomarkerite alusel selgitada välja reostunumad ja vähemreostunud piirkonnad Soome lahe Eesti rannikumeres.Kirje Effects of environmentally relevant concentrations of microplastics on amphipods(Elsevier, 2022) Rani-Borges, Barbara; Meitern, Richard; Teesalu, Paul; Raudna-Kristoffersen, Merilin; Kreitsberg, Randel; Heinlaan, Margit; Tuvikene, Arvo; Ivask, AngelaLack of microplastics (MP) toxicity studies involving environmentally relevant concentrations and exposure times is concerning. Here we analyzed the potential adverse effects of low density polyethylene (LDPE) MP at environmentally relevant concentration in sub-chronic exposure to two amphipods Gmelinoides fasciatus and Gammarus lacustris, species that naturally compete with each other for their habitats. 14-day exposure to 2 μg/L (8 particles/L corresponding to low exposure) and 2 mg/L (~8400 particles/L, corresponding to high exposure) of 53–100 μm LDPE MP were used to assess ingestion and egestion of MP, evaluate its effects on amphipod mortality, swimming ability and oxidative stress level. Both amphipod species were effectively ingesting and egesting LDPE MP. On the average, 0.8 and 2.5 MP particles were identified in the intestines of each amphipod exposed to 2 μg/L and 2 mg/L LDPE MP, respectively. Therefore, intestinal MP after 14-day exposure did not fully reflect the differences in LDPE MP exposure concentrations. Increased mortality of both amphipods was observed at 2 mg/L LDPE MP and in case of G. lacustris also at 2 μg/L exposure. The effect of LDPE on swimming activity was observed only in case of G. fasciatus. Oxidative stress marker enzymes SOD, GPx and reduced glutathione GSH varied according to amphipod species and LDPE MP concentration. In general G. lacustris was more sensitive towards LDPE MP induced oxidative stress. Overall, the results suggested that in MP polluted environments, G. lacustris may lose its already naturally low competitiveness and become overcompeted by other more resistant species. The fact that in the sub-chronic foodborne exposure to environmentally relevant and higher LDPE MP concentrations all the observed toxicological endpoints were affected refers to the potential of MP to affect and disrupt aquatic communities in the longer perspective.Kirje Improving administrative effectiveness of lake management in the frames of River Basin Management Plans : Implementation Plan(2014) Tuvikene, Lea; Sammalkorpi, Ilkka; Kreitsberg, Randel; Soo, Kristjan; Tuvikene, Arvo; Estonian University of Life SciencesFresh waters make only 3% of the global water resources. Freshwater lakes, including reservoirs and ponds, are important elements for communities and their relevance is increasing. Lake ecosystems and their catchments have provided several societally valuable benefits and ecosystem services like shelter, drinking water, bathing water, food, a means of travel and wealth in a number of ways and allowed whole cultures to develop. Lakes have values associated with well-being and relaxation, their proximity has catalyzed rural development and been important in the regional socio-economic development. Lake districts are often very popular destinations for domestic and foreign tourism and visitors. Eutrophication and its ecological consequences, pollution, over abstraction and invasive species are serious threats and increase the need for restoration and management to prevent the potential adverse economic and social impacts. There is increasing evidence that lakes are affected by climate change. Lake management is for these reasons an important part of sustainable regional development as set by Lisbon and Gothenburg agreements. However, the most significant piece of legislation in response to the increasing threat of pollution and the increasing demand from the public for cleaner lakes, rivers and beaches and freshwater biodiversity, is the EU Water Framework Directive (WFD). This Directive is unique in that it sets out an established framework for the protection of all water bodies (including lakes) and for all EU member states to achieve good water ecological status by December 2015. This objective is likely to be achieved in slightly over half (53 %) of EU waters (A blueprint…, 2013) and, therefore, more effort need to be scheduled for the following 6-year periods of WFD. The economic values of attractive, clean lakes are well established. There is a rising appreciation of good quality lakes across Europe. More intensive lake protection through sharing good practices with European lake managers and the regional influencing bodies is critical if we want to improve the current quality of lakes in Europe and to build long term capacity for sustainable use of lakes.Kirje Järvede haldamine vesikondade veemajanduskavade raames : tegevuskava(2014) Tuvikene, Lea; Sammalkorpi, Ilkka; Kreitsberg, Randel; Soo, Kristjan; Tuvikene, Arvo (koostaja); Eesti MaaülikoolVaata ka EMU DSpace'is Viitna Pikkjärve, Veisjärve, Verevi järve ja Harku järve meetmekavasid.