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Aktivita raka mramorovaného v závislosti na reprodukčním cyklu
MARKOVÁ, Kateřina
The aim of this thesis was to elaborate a literature review on the topic of crayfish activity, in particular their feeding activity and the use of shelters, including an emphasis on the role of sex and the reproductive cycle. I also focused on the characteristics of the marbled crayfish, Procambarus virginalis Lyko, 2017 and its usability as a model organism. The experimental part of the thesis focused on comparing three groups of female marbled crayfish (with ovulum, with glair glands and without ovulum). Experiments have been carried out using a method for ecological assessment of feeding behavior and predator-prey relationship in various prey densities in the form of larvae of buzzer midge Chironomus plumosus (Linnaeus, 1758) by functional response analysis and subsequently tested for the effect of shelter presence at uniform prey densities levels. In our experiment, all three groups of tested females showed a type II functional response typical of predators. The results indicate that females without ovulum have been the most active in terms of food collection in all cases, with a generally positive effect of the presence of shelter. Females with employed ovulum are generally less active in terms of consumption, processing and overall aktivity due to hormonal, physiological and consequently behavioural changes. Females with glair glands behaved similarly to females with ovulum in our experiments, being more cautious and less active than females without ovulum. This was probably due to their increased gonadosomatic index (GSI) and, conversely, their decreased hepatopankreas to total body weight ratio, which renders these females unable to physiologically ingest large amounts of submitted food. Female GSI decreases again after ovulation, nevertheless, even females with already employed ovulum did not consume more food, as females prefer safety at this stage of the reproductive cycle. They are less active, move more slowly, spend more time in a shelter, tend to their eggs, and thus cannot devote themselves fully to hunting and prey processing. Regarding its life strategy, the marbled crayfish is a generally suitable model organism for use in various areas of research, however, it is important to take into account its rapid life and reproductive cycle and adapt the conditions of the given experiments to this fact, as the parallel use of female marbled crayfish at various stages of the reproductive cycle can modulate results in terms of their activity. Certain differences in the presented results may also be due to the origin of the experimental animals, as with very few exceptions all performed experiments with marbled crayfish have been carried out using laboratory individuals. A number of conditions that change seasonally in nature have been kept constant in the laboratory. Therefore, it is important to keep in mind that in wild, crayfish are also exposed to both biotic (predation pressure of various species of fish, birds or mammals) and abiotic (changes in temperature and water chemistry) factors that can influence food activity. Nevertheless, we assume that the patterns observed here will also be valid for female crayfish living in the wild nature. However, the lack of similar experiments leading to the elucidation of female activity depending on the stage of the reproductive cycle provides a room to investigate other, not just crayfish species.
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Molluscs as a new model system in molecular biology
Ber, Tobiáš ; Svoboda, Petr (advisor) ; Pergner, Jiří (referee)
Molluscs form the second largest animal phylum and are of great biological and economic significance. Their distinct evolutionary adaptations enabled them to inhabit a broad range of environments, with many of them invading new areas and becoming invasive pest species. Despite their importance, molluscan model systems have not received attention they deserve. In this bachelor thesis, I have reviewed the current state of molluscan model systems in molecular biology and analyzed their significance for more common use. From available data, it is apparent that the already established molluscan models are either marine or fresh-water, and therefore require more complex logistics and maintenance in order to set up a laboratory culture. To remedy the problem of aquaculture, the use of terrestrial gastropods was proposed. Here, I suggest that gastropods genus Deroceras have a good potential to become a new prominent molluscan model system in molecular biology.
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Characterization of the porcine induced pluripotent stem cells
Svobodová, Eliška ; Vodička, Petr (advisor) ; Tlapáková, Tereza (referee)
Induced pluripotent stem cells (iPSCs) are the cells established by introducing several transcription factors into the somatic cells and culturing them in embryonal stem cell (ESCs) culture conditions. Factors used for the establishment of the first iPSCs are OCT3/4, SOX2, KLF4 and c-MYC. IPSCs created by these means resemble closely to the ESCs. IPS technology may be used to derive iPS cells of individual pacients and apply these cells for their treatment in the cases where the use of ESCs represents an ethical and imunological problem. Therefore, it is important to establish an appropriate animal model for the longtime safety testing of iPSCs before acceding to their medicinal aplication.
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Diversity, distribution, phylogeny and ecology of the genus Micrasterias (Desmidiales)
Trumhová, Kateřina ; Šťastný, Jan (advisor) ; Bestová, Helena (referee)
The genus Micrasterias comprises one of the most beautiful organisms. It attracts, due to its spectacularly shaped cells, the attention of scientist and amateur biologist almost for almost 200 years. This thesis summarizes the current knowledge about these extraordinary organisms. The first part deals with the morphology and the life cycle of these algae. They share a unique type of reproduction (conjugation) with the other representatives of the class Zygnematophyceae. The second part concerns phylogeny of this genus. Several morphologically distinct species have been revealed with the aid of molecular phylogenetic methods to belong to the genus Micrasterias. A polyphasic evaluation of three species complexes within this genus also revealed an extensive hidden diversity. The last chapters summarize the knowledge about the influence of hidden diversity and accelerated morphological evolution on our understanding of diversity and biogeography of these organisms.
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Gene expression differences during regeneration in model organisms
Netušil, Jiří ; Šindelka, Radek (advisor) ; Hason, Martina (referee)
With new progressive methods allowing us to study natural regeneration in model organisms, we have an opportunity to gain important insights into the very essence of this process. These insights might help us radically improve the current state of therapeutic approaches based on tissue replacement. Many different animal models display an incredible ability to restore various body parts, allowing them to escape predators and avoid premature death. While invertebrate models give us a chance to investigate the fundamental elements of regeneration, vertebrates represent systems often more resembling human biology. This thesis outlines the variability of regeneration in frequently studied model organisms with a special emphasis on the impact of gene expression. Keywords: regeneration, model organism, gene expression, injury
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Diversity, distribution, phylogeny and ecology of the genus Micrasterias (Desmidiales)
Trumhová, Kateřina ; Šťastný, Jan (advisor) ; Bestová, Helena (referee)
The genus Micrasterias comprises one of the most beautiful organisms. It attracts, due to its spectacularly shaped cells, the attention of scientist and amateur biologist almost for almost 200 years. This thesis summarizes the current knowledge about these extraordinary organisms. The first part deals with the morphology and the life cycle of these algae. They share a unique type of reproduction (conjugation) with the other representatives of the class Zygnematophyceae. The second part concerns phylogeny of this genus. Several morphologically distinct species have been revealed with the aid of molecular phylogenetic methods to belong to the genus Micrasterias. A polyphasic evaluation of three species complexes within this genus also revealed an extensive hidden diversity. The last chapters summarize the knowledge about the influence of hidden diversity and accelerated morphological evolution on our understanding of diversity and biogeography of these organisms.
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Characterization of the porcine induced pluripotent stem cells
Svobodová, Eliška ; Vodička, Petr (advisor) ; Tlapáková, Tereza (referee)
Induced pluripotent stem cells (iPSCs) are the cells established by introducing several transcription factors into the somatic cells and culturing them in embryonal stem cell (ESCs) culture conditions. Factors used for the establishment of the first iPSCs are OCT3/4, SOX2, KLF4 and c-MYC. IPSCs created by these means resemble closely to the ESCs. IPS technology may be used to derive iPS cells of individual pacients and apply these cells for their treatment in the cases where the use of ESCs represents an ethical and imunological problem. Therefore, it is important to establish an appropriate animal model for the longtime safety testing of iPSCs before acceding to their medicinal aplication.
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