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Effect of triclosan on in vitro meiotic maturation of porcine oocytes
Straková, Johana ; Petr, Jaroslav (advisor) ; Frolíková, Michaela (referee)
Meiotic maturation of oocytes is a key phase in the development of female gametes. The natural physiology of oogenesis and meiotic maturation is currently being influenced by a number of anthropogenic environmental contaminants. These compounds include triclosan. Triclosan (5- chloro-2-(2,4-dichlorophenoxy) phenol) is an antibacterial substance commercially used in cosmetic and disinfectant products. This compound enters the human body by absorption through the skin and mucous membranes. Its presence has been demonstrated in blood, urine, breast milk, liver and adipose tissue. Triclosan is classified as an endocrine disruptor, yet its consumption continues to increase worldwide. The aim of this study is to evaluate the effect of low doses of triclosan on selected markers of meiotic maturation of porcine oocytes in vitro. This work describes the negative effects of triclosan and triclosan in combination with bisphenol S on the meiotic maturation of porcine oocytes in vitro. Furthermore, the effect of these substances on the increased percentage of abnormal meiotic spindles and the stability of the microtubules of the meiotic spindle was demonstrated. Effects on mitochondria and epigenetic effects of triclosan were not proved. The results highlight the risks associated with the commercial use of...
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Role of microvesicles and exosomes in reproduction of mammals
Straková, Johana ; Frolíková, Michaela (advisor) ; Petr, Jaroslav (referee)
Microvesicles and exosomes are extracellular vesicles of nanometer size derived from cell membranes. Due to their ability to transfer proteins, lipids and RNA, microvesicles and exosomes are now considered to be a common form of communication between somatic cells. Microvesicles and exosomes have been detected in the reproductive organs of male and female mammals, where they mediate the transport of molecules between cells and thus promote their communication during physiological and pathological processes. Signalling through microvesicles and exosomes is involved in sperm maturation processes, which enrich these vesicles for molecules required for motility and fertilization capacity. Similarly, during oocyte maturation, microvesicles promote communication between follicle cells and its growth. During fertilization, the molecules transported by microvesicles promote capacitation and acrosomal reaction and, after gamete fusion, support the developing embryo and its subsequent implantation in the uterus. The main focus of this bachelor thesis is to discuss the role of microvesicles and exosomes in various processes in mammalian reproduction from sperm and egg maturation to successful fertilization and embryo implantation. A significant part of the thesis is devoted to the presentation of molecules...
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