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Gametogenesis and Fertilization in Humans
Crhová, Michaela ; Pavlasová, Lenka (advisor) ; Ehler, Edvard (referee)
This bachelor thesis summarises the topic of gametogenesis and fertilization in humans. A search in available literature was performed. The thesis concisely describes the cell cycle and cell division. The main focus is on meiosis, a reductional division that takes the lead part in sexual reproduction. The process of this division is described in detail, and also the mechanism that creates variability of protected cells is described. The product of meiosis is gametes, also known as germ cells. Production of these cells is a key moment in sexual reproduction. This thesis approaches this topic in the context of evolutionary biology and explains its importance in the survival of species on Earth. The main topic of the thesis is the production and maturing of human germ cells. This process is called gametogenesis. This thesis provides a cohesive description of the reproduction system of both sexes and describes the gradual maturing of the germ cells in gonads. The structure of both gametes, egg, and sperm is described with emphasis on the parts of these cells that take part in the process of fertilization. Female reproductive cycles are depicted, and their connection is explained. In contrast to this periodicity, the male continual maturing is also explained. This thesis compares the main differences in...
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Variability of the domestic chicken breeds in selected immunological traits of hen and egg
Bílková, Barbora ; Vinkler, Michal (advisor) ; Plachý, Jiří (referee) ; Trefil, Pavel (referee)
The avian immune system is a complex system of defence mechanisms that protect bird hosts against threats from ubiquitous pathogens. According to the co-evolutionary models, variability in immune traits of hosts is the key component providing ability to adapt and enhance their defence mechanisms in presence of constant selective pathogen pressure. Domestic chicken (Gallus gallus f. domestica) is used as a model organism in avian biology and also is one of the most important food-producing animals, not only for their meat but also for the egg production. Unfortunately, in research usually only inbred chicken lines are used and modern poultry husbandry is tight with unilateral breeding towards highly productive breeds. Those approaches decrease intra-population polymorphism in chickens. However, especially in case of farm animals, searching and extending the pool of immune variability and enhancing pathogen resistance is crucial for sustaining healthy and biologically secure populations and their products. Morphologically highly distinct traditional chicken breeds, which have evolved for hundreds years under different selective pressures, may represent this desirable immunological variability. In my thesis I described variability in chosen immunological traits, haematological parameters and proteomic...
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The role of integrins in gametes prior to fertilization and during their interaction
Foldynová, Veronika ; Komrsková, Kateřina (advisor) ; Tlapáková, Tereza (referee)
Integrins are heterodimeric transmembrane glycoproteins that represent a large group of cell adhesion receptors involved in cell-cell, cell-extracellular matrix and cell-pathogen interacti- ons. Up to now, 24 different integrin heterodimers have been detected in mammals. They are involved in a wide range of processes such as immune response, lymphocyte homing, platelet aggregation, also in wound healing, cell differentiation, migration, proliferation and even in cell survival. Integrins have also been detected on germ cells and are now known to play an important role in reproductive processes such as fertilization, embryo implan- tation, and embryonic development. The main aim of this thesis is to introduce integrins from the perspective of reproduction, integrin physiology, occurrence and localization of individual subunits in male and female germ cells. A significant part of the work is devoted to a discussion of the role of integrins in gametes, both during maturation processes (egg maturation in the ovary, capacitation and the acrosomal reaction of sperm), in sperm mi- gration, oviductal reservoir formation and their direct and indirect involvement in adhesion and fusion of the gametes during fertilization. Keywords: integrins, sperm, egg, fusion, fertilization
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Variability of the domestic chicken breeds in selected immunological traits of hen and egg
Bílková, Barbora ; Vinkler, Michal (advisor) ; Plachý, Jiří (referee) ; Trefil, Pavel (referee)
The avian immune system is a complex system of defence mechanisms that protect bird hosts against threats from ubiquitous pathogens. According to the co-evolutionary models, variability in immune traits of hosts is the key component providing ability to adapt and enhance their defence mechanisms in presence of constant selective pathogen pressure. Domestic chicken (Gallus gallus f. domestica) is used as a model organism in avian biology and also is one of the most important food-producing animals, not only for their meat but also for the egg production. Unfortunately, in research usually only inbred chicken lines are used and modern poultry husbandry is tight with unilateral breeding towards highly productive breeds. Those approaches decrease intra-population polymorphism in chickens. However, especially in case of farm animals, searching and extending the pool of immune variability and enhancing pathogen resistance is crucial for sustaining healthy and biologically secure populations and their products. Morphologically highly distinct traditional chicken breeds, which have evolved for hundreds years under different selective pressures, may represent this desirable immunological variability. In my thesis I described variability in chosen immunological traits, haematological parameters and proteomic...
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Influence of the chicken breeding method on the selected chemical constituents of chicken eggs
Michalec, Adam ; Vespalcová, Milena (referee) ; Pořízka, Jaromír (advisor)
This diploma thesis is focused on the analysis of egg yolks and egg whites from chickens raised with different breeding methods in the Czech Republic using three analytical methods. The Kjeldahl method was used to determine the proteins, the Soxhlet method was used to determine the lipids and ICP-OES was used for elemental analysis. The theoretical part describes the history of chicken breeding, marking and distribution of eggs and composition of eggs based on various aspects. The main point was the separation of egg yolk and egg white and the subsequent description on the chemical and physiological level. Principle of used methods is also described. The experimental part deals with the preparation of samples, calibration samples and process analysis. All the results of analysed substances are summarized, statistically evaluated and compared with the other literature. For this analysis were used eleven different types of eggs from the Czech Republic from six different categories.
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Role of tetraspanin network during sperm-egg interaction and fusion
Černá, Pavlína ; Hortová, Kateřina (advisor) ; Petelák, Aleš (referee)
Fusion of sperm and egg is a crucial moment of the fertilization process which is fundamentally urged by tetraspanin superfamily proteins whose interactions allow mutual interaction of gamets and their subsequent fusion. Tetraspanins are 25-50 kD transmembrane proteins whose various kinds are found in most mammalian cells. Four transmembrane domains containing key amino acid residues indicating their function are their specificity. The essential feature of tetraspanins is their ability to form membranes lateral bonds which are reached thanks to large complexes with other proteins that form the so-called tetraspanin network. The interaction with other proteins and tetraspanins is important for a cell adhesion to the extracellular matrix, adhesion to the other cells, and it plays a role in signal transduction. This bachelor thesis describes and summarizes the role of tetraspanin networks during fusion of egg and sperm. A general introduction of tetraspanins, their structure and functions in cellular processes and interactions leading to the formation of tetraspanin networks which are the key point in fertilization, are given. A description of the fertilization process itself, the protein interactions and changes which precede it in included. The latest findings of the topic from the viewpoint of...
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Factors affecting deposition of selected antimicrobial substances into the egg structures
Pokorná, Monika ; Javůrková, Veronika (advisor) ; Svobodová, Jana (referee)
Both during the ovogenesis and immediately after the laying is a bird egg exposed to strong pressure from the microorganisms which are able to penetrate the egg through eggshell pores and infect its inner structures. With regard to the proved negative effects on hatchability, viability and phenotype of offspring, a cascade of obstacles has evolved which are able to minimize the risk of bacterial infection. The deposition of antimicrobial components into the eggshell and the egg white is considered to be one of them. A whole group of egg white proteins belong to them, among which lysozyme and ovotransferrin, which are also partially deposited into the eggshell and cuticular layer of the eggshell, dominate with their antimicrobial effect. The implication of the newest studies is that the microbial protection of the egg can be also performed by the eggshell pigments - biliverdin and protoporphyrin, which protect the egg from being colonized by microorganisms with an increased UV light and regulation of conductivity and water vapour condensation on the egg surface. Even though the presence of these antimicrobial components in different structures of the egg has been proved, there is no known comparative study which addresses the relation between deposition of selected antimicrobial components into...
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Study of the reproductive biology of the crayfish - mating, laying eggs and morphological structure of the male and female gametes
KUBEC, Jan
In the nature, crayfish are represented like predators or a part of food base of some fish. Also in free waters they acts as detrivors and are an important element in the nutrient and energy circle in aquatic ecosystem. The crayfish weren't able to avoid negative impacts of anthropogenic activities such as water pollution and devastation of habitats. For these reasons reproduction of the crayfish is necessary in hatcheries and farms. The main aim of my work was to study the reproductive biology of the crayfish focused on the process of mating, the interval between mating and laying eggs, fertilization and morphological structure of the male and female gametes. Among the secondary objectives there was included using of repeated electrostimulation of the crayfish and the possibility of hybrids of the noble crayfish (Astacus astacus) and the narrow-clawed crayfish (Astacus leptodactylus). The observation of the period of reproduction was realized on representativies of the noble crayfish and the narrow-clawed crayfish throughout natural mating in the tanks. The structure of gametes was observed on the samples taken from thenoble crayfish (Astacus astacus), the narrow-clawed crayfish (Astacus leptodactylus), the signal crayfish (Pacifastacus leniusculus), the red swamp crayfish (Procambarus clarkii) and spinycheek crayfish (Orconectes limosus). The experiments were carried out during the autumn season in 2012 and 2013. The results of observations of the reproduction of crayfish made us clear as for the period and intervals for all phases of the process of mating crayfish. For females the noble crayfish and the narrow-clawed crayfish was found oviposition without the presence of males. Their individual components have been described by using ultrastructure of males and female gametes. Repeated electrostimulation showed at the family Astacidae as a suitable tool for collecting large mass of sperm material. Hybridization experiment proved that it can occur to mate the two species of crayfish in areas where they occur simultaneously. These experiments helped to further knowledge of reproductive biology of crayfish.
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The adjustment of the feed ration for laying hens in order to improve the strength and the hardness of eggshells
HEINDL, Jakub
This major thesis expands the issue of the bachelor thesis "The issue of raising laying hens considering on introduction of enriched cages" and adds new knowledge relating to the topic feed rations and their influence on the final production. The theoretical part of the thesis analyses the basic theoretical concepts cohering with this topic, focused on creating a comprehensive overview of the structure and quality of the eggs, the basic ingredients in the feed rations, qualitative parameters of grapes as the modified additive provided by us and last but not least there is processed the recent overview of the current state of large-scale farmers in the Czech republic. The practical part of the thesis aims to test the effect of the proposed feed with an additive in the form of the crushed grape seeds, on the strength of the eggshell, by homogeneous samples of the breeds through from us proposed measuring instrument. Subsequently, a statistical evaluation of measured results is realized. In conclusion, the consideration is extended to the economic evaluation of costs and profits in case of the implementation of the suggested feed ration into practice in order to quantify the difference compared to the commonly used feed ration.
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