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Genetic structure of mammalian invasive populations on islands
Loudová, Miroslava ; Černá Bolfíková, Barbora (advisor) ; Hájková, Petra (referee)
Biological invasion is understood as introduction, establishment and expansion of organisms into new, non-native area. This is a natural process that is significantly compounded by human activities and is one of the factors that threaten biological diversity and stability of natural ecosystems. Understanding to the evolution and current status of invasive populations is especially important for planning a project to eradicate invasive species from certain areas to avoid their negative impact on the environment. One option for the research of the invasive populations and their history is the analysis of genetic material. This thesis summarizes the current knowledge on invasive populations of small mammals on the islands, with the focus on genetic studies. Specifically, the study of Norway rats (Rattus norvegicus) on Moturemu island and five archipelagos off the coast of Brittany; black rats (Rattus rattus) on Congo Cay, Madagascar, Guadeloupe Archipelago, Sainte Anne Archipelago and Canary Islands; Pacific rats (Rattus exulans) on Tetiaroa Atoll; house mice (Mus musculus) on Marion Island; house mice (Mus musculus domesticus) on Kerguelen Archipelago; red squirrels (Sciurus vulgaris) on Jersey island, West European hedgehogs (Erinaceus europaeus) in New Zealand; pygmy shrews (Sorex minutus) in Ireland and...
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Regeneration of heart muscle in vertebrates
Bergelová, Barbora ; Krylov, Vladimír (advisor) ; Mašek, Jan (referee)
Fish model organisms such a Danio rerio have the ability to regenerate heart muscle during its whole lifespan. Compared to Danio rerio, the ability of heart regeneration differs in amphibians. While the newt has the ability to regenerate its heart tissue throughout its whole life, the Xenopus leavis loses its power when it goes through metamorphosis. The regenerative ability varies not only between genera but also between species. For example compared to Xenopus leavis, Xenopus tropicalis has the ability to regenerate its heart tissue even in adulthood. Mammals have a very limited ability to regenerate their heart muscle. We can observe the ability to regenerate heart after injury in mice and humans for a very limited time of a few days after birth. In adulhood the heart is healed via rich collagen scar. It is vital that signaling pathways in highly regenerative model organisms are intensively studied, so that the knowledge gained may help us in the treatment of heart injuries in humans. Key words: regeneration, heart muscle, repair, zebrafish, mammals, amphibians, heart development, vertebrates
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The importance of water sources for space-use of mammals in African savannah
Homoláč, David ; Hořák, David (advisor) ; Brandlová, Karolína (referee)
African savannas are seasonal ecosystems experiencing a significant dry period each year. During the dry season, water scarcity has both, spatial and temporal consequences on the movements of large mammals. Some mammals can cope with these resource restrictions better than others. These water independent mammals predominantly feed on browse (giraffe, kudu, eland) and can be found further from water sources. However, these mammals can utilize areas near rivers as these areas provide food resources. Water dependent species are predominantly grazers and non-ruminants (zebra, wildebeest, elephant). Water shortage during a dry season restricts the movements of these species, which can be generally found in the vicinity of water bodies. Carnivore species (lions) react on the spatial restrictions of ungulates by adjusting their hunting areas to the vicinity of water sources. Both intra-guild (African wild dog) and inter-gild prey species (ungulates) develop anti-predatory strategies such as temporal and spatial segregation. African wild dogs use dens far from water points and ungulate species use to drink during daytime when lions are not active. Spatial and temporal segregation are also strategies to cope with competitors. Daily patterns of water point visitations can vary suggesting other factors...
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Regeneration of heart muscle in vertebrates
Bergelová, Barbora ; Krylov, Vladimír (advisor) ; Mašek, Jan (referee)
The model organisms like for example the fish Danio rerio has the ability to regenerate heart muscle during its whole lifespan. Compared to Danio rerio, the ability of heart regeneration differs in amphibians. While the newt has the ability to regenerate its heart tissue throughout its whole life, the Xenopus leavis loses its power when it goes through metamorphosis. The regenerative ability does not only differ between salamanders and claws. We can observe some differences between regeneration of Xenopus tropicalis and Xenopus leavis too. Compared to Xenopus leavis, Xenopus tropicalis has the ability to regenerate its heart tissue even in adulthood. Mammals have a very limited ability to regenerate their heart muscle. We can observe the ability to reverse heart damage in mice and humans for a very limited time of a few days after they are born. In adulhood they repair the heart muscle and the rich collagen scar is formed. It is vital that signaling pathways in regeneration of model organisms is researched further, so that the knowledge gained may help us in the treatment of heart injuries in humans. Key words: regeneration, heart muscle, repair, zebrafish, mammals, amphibians, heart development, vertebrates
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Molecular mechanisms of mammalian circadian clocks, its sensitivity to constant light and aging
Novosadová, Zuzana ; Sumová, Alena (advisor) ; Doležel, David (referee) ; Mráz, Miloš (referee)
Many processes in mammalian body exhibit circadian rhythms. These rhythms are driven by an intricate system composed of the central pacemaker, suprachiasmatic nuclei (SCN) in the brain, which entrains the peripheral oscillators in various organs, such as pancreas, liver, colon and lungs. Circadian clocks are autonomously driven in each cell based on molecular circuits involving so called clock genes, such as BMAL, CLOCK, PER and CRY. Age- dependent impairment of physiological functions of mammalian body, such as behaviour and metabolic functions, has been well documented. However, it has not been fully elucidated whether the impairment is linked with worsening of the circadian clock function. The aim of our study was to find out whether i) aging affects basic properties of the circadian clock in SCN and peripheral organs, such as pancreas, colon, liver and lungs, ii) aging- induced changes in glucose homeostasis affect the properties of the circadian clock in the pancreas, and iii) the sensitivity of circadian clock in SCN and peripheral organs to disturbances in environmental lightning conditions is altered during aging. We used groups of adult (9 months) and aged (25 months) animals which were subjected to 3 different light regimes, namely to light/dark regime (LD 12:12), constant light (LL) and...
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Cellular and molecular basis of a skin regeneration in amphibians and mammals
Hybešová, Michaela ; Krylov, Vladimír (advisor) ; Jendelová, Pavla (referee)
Wound healing of skin in mammals and its regeneration in Amphibians are crucial biomedicine topics in the last few decades. The most important aspect in humans is the scrarring proccess and the effort to substitute it with the regeneration producing functional and differentiated tissues. To modulate the formation of scar it is neccessary to compare both proccesses. The core animal model is axolotl (Caudata) where regeneration takes place during whole lifespam. On the other hand, in frogs (Anurans) this phenomenon is restricted up to metamorphosis. After metamorphosis, the immune system of Anurans is similar if compared to mammals. Similarly, the transition from early embryonic development in mammals, where the fetus was able to completely regenerate damaged tissue to an adult type of healing, goes hand-in-hand with the development of the immune system and structural differentiation of damaged tissue. Thus, the inflammatory cells and their regulation, the formation of ECM, which includes fibroblast proliferation, and the production of appropriate cytokines are key factors that distinguish the process of healing with and without scarring.
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Population trends of African mammals
Homová, Viktória ; Storch, David (advisor) ; Hulva, Pavel (referee)
The African continent is known for its rich species diversity (biodiversity). We can read about the decline in African mammal populations in various sources. The main reasons of decline include loss of habitats and animal hunting. In spite of the general idea of decline mammals, in some cases the population trend is stable or growing. The aim of my thesis is to explore and summarize what is really known about the changes in the populations of all known mammalian species over the past decades. The attention of public is mainly oriented towards large flagship species, which are very well studied and various measures are put in place to protect them, especially in protected areas. The most marked decline in the number of individuals occurs in the western part of Africa, which is probably caused by a combination of lack of financial and human resources in animal protection, a large range of biotope damage and growing bushmeat trade. Species with increasing population trends are predominantly in South Africa, where there is an improvement in the management and the protection of wildlife receives more attention. Considering small mammals, there is, in most cases, no relevant data available to help determine their population trend. The population trends of species residing in the tropical rainforests are...
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