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The influence of oxidative stress on mammalian sperm quality and fertilization ability.
Dudková, Barbora ; Komrsková, Kateřina (advisor) ; Svoboda, Petr (referee)
This bachelor's thesis deals with the oxidative stress and its influence on structures and physiologic functions of mammalian sperm. Oxidative stress is a consequence of imbalance between pro-oxidants and anti-oxidants in the body. It is associated with impaired quality of sperm and it is considered to be one of the major reasons of male infertility, including humans. This work is presented as a research review targeting how and where reactive oxygen species are generated in the male reproductive tract. It summarizes specific structures and physiologic functions that are influenced by reactive oxygen species either positively or negatively and it also covers a protective role of antioxidants in seminal fluid.
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Effect of cryopreservation on mouse sperm.
Veselá, Kateřina ; Pěknicová, Jana (referee) ; Hortová, Kateřina (advisor)
Cryopreservation or freezing of sperm in the reproductive biology is still actual topic. Today is the only method used for sperm storage, whether for the purposes of assisted reproduction, or for scientific purposes. However, this method has a negative impact on such stored cells and is therefore still a subject of many studies. Among the main causes of sperm damage in rodents there are inappropriately selected cryoprotective agents, poor or no elimination of oxidative stress generated during cryopreservation, as well as a poorly chosen speed and temperature of freezing. Correctly chosen procedures and the composition of the media in which sperm are stored, can significantly affect the quality of sperm. This bachelor theses focuses on the influence of cryopreservation on mouse spermatozoa. The main impact of this method includes the effect of freezing on sperm DNA, plasma membrane, acrosome, and sperm motility.
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Influence of estrogens on mammalian sperm.
Šidlová, Adéla ; Šebková, Nataša (referee) ; Hortová, Kateřina (advisor)
For many years, estrogens have been considered typically female sex hormones. It is now certain that they are also very important in the regulation of male reproduction, whether their effect is positive or negative. Endogenous estrogens in mammalian males are an important part of the endocrine system. Estrogens play an important role in the growth and maintenance of bone mass, as well as in the development of germ cells and in the marches of spermatogenesis. Healthy sperm are essential for successful reproduction. Effect of endogenous estrogens is partly involved in the regulation of proper development of sperm. Besides the positive effect of endogenous estrogens, there is also a negative effect of estrogens from the external environment, so-called environmental estrogens. Between environmental estrogens are man-made chemicals, xenoestrogens, which increasingly contaminate the environment. Hazards of these estrogenic substances in nature is hidden in their ability to act as endocrine disruptors, which cause defects in many aspects of mammalian reproduction. With regards to the fact that there are more and more substances in current environment that can interfere with hormonal path of mammalian reproduction, it is important to look at this issue. Reproductive disorders that may be caused by...
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Sperm acrosomal reactien in selected species of mammals
Frolíková, Michaela ; Stopka, Pavel (advisor) ; Jonáková, Věra (referee) ; Petr, Jaroslav (referee)
Mammalian sperm must undergo the process of capacitation - series of physiological and biochemical modifications prior fertilization. In last stage of capacitation sperm undergoes acrosome reaction (AR). During AR the cell membrane of the sperm fuses with the outer acrosomal membrane and the contents of acrosomal vesicle are released into extracellular space. Sperm which did not undergo AR or sperm missing acrosome at all are unable to fertilize. AR results into dramatical changes in the sperm head. Most of the proteins present in plasmatic and outer acrosomal membrane are reorganized or lost. There are also significant changes in cytoskeletal and intraacrosomal proteins are released to extracellular space uncovering new surface domains. Some sperms undergo AR even without presence of inductor of AR during capacitation in vitro. This event is called spontaneous (accelerated) AR. The latest research indicates that spontaneous AR is natural part of the process of fertilization. Field mice (Apodemus) show high level of promiscuity leading to significant risk of sperm competition. Unique reproduction strategy where the sperms form so-called sperm trains was evolved in field mice. Spontaneous AR is probably enabling the dissociation of sperms from the sperm train. The spontaneous AR rate is dependent on...
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Cryopreservation of common carp (\kur{Cyprinus carpio} L.) sperm under different freezing conditions
SOCHOROVÁ, Denisa
In the present study, we examined several cryoextenders previously used by several authors and various freezing protocols to determine the relative importance of each parameter on sperm freezing. The effects of controlled seeding and changes in cooling rate at different stages of freezing were also examined. Sperm samples from seven individual carp males were frozen in 0.5 ml straws by conventional freezing. Cooling rates were determined by monitoring the sample's internal temperature. We compared four freezing protocols, which involved placing sperm samples at various levels (1, 3, 6, and 9 cm) above the liquid nitrogen (LN) surface (corresponding to -190, -150, -110, and -70 °C, respectively) for 20 min followed by transferring the samples into LN. Freezing at 3 cm above the LN surface resulted in the highest motility (33 ? 8 %) and velocity (118 ? 9 ?m/s) of spermatozoa after thawing and diluting in swimming medium. We determined that -90 °C is an optimal temperature at which immersing the samples in LN does not affect sperm motility after thawing. The sperm motility of samples immersed in LN before or immediately after the crystallisation point (-16 °C) was 0 %. Motility of spermatozoa cryopreserved with or without a seeding procedure was not significantly different after thawing. Therefore, we hypothesise that supercooling the sample during the conventional freezing procedure is not the main damaging factor during carp spermatozoa cryopreservation.
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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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Male Sterlet (Acepenser ruthenus) Fertility under Fish Farming Conditions of the Czech Republic
SCHACHERLOVÁ, Jiřina
Currently, fish fertility studies are mainly focused on female fertility. Studies showing fertility of male fish of any kind are missing to a large extent. The main objective of my thesis was to identify what level of fertility is achieved by male sterlet (Acipenser ruthenus) in the conditions of fish farming in the Czech Republic. Male fish from the Vodňany farm where the raised population comes from Russia was compared to male fish from Pohořelice where the raised population comes from Danube. The total comparison test involved 49 pieces of fish. Following stripping to collect semen from male fish, the concentration of sperm (.109.ml-1) was measured in a 1 ml-1 semen sample. Consequently, a sperm count per 1 kg-1 male fish (.109.ml-1) and a sperm volume per 1 kg-1 male fish (ml-1) and a total male fish sperm count (.109) were measured. The highest values of weight identified in male fish was measured in the Pohořelice fish farm. The lowest values of weight was measured in male sterlet of the Vodňany fish farm. The highest as well as lowest volumes of collected semen per 1 kg-1 male fish were identified in Vodňany. However, the average volumes of both cultures were not significantly different. It was concluded by comparison that collected semena volume does not depend on the weight of said fish. Also, the relative fertility was significantly different between male fish of the same population. The highest and lowest sperm count per 1 kg-1 male sterlet were identified in Vodňany. The average minimum and maximum sperm counts per 1 kg-1 male fish were different very much which shows that a greater number of male fish should be used for spawn to ensure sufficient egg fertilization. The average overall fertility values in both cultures are very similar and mainly different in specific specimen of the same culture as well as between those cultures. The results showed that a total sperm count in semen depends on the volume of collected semen. It was further concluded that sterlet fertility does not depend on the size (weight) of fish.
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The electrostimulation the spermiation in the crayfish
KUBEC, Jan
The crayfish are important and indispensable animals in aquaculture. In the aquatic environment, they have a role as predators, food for other fish, detrivors and they are an important element in the circulation of the energy and the nutrient in the aquatic ecosystem. Today, number of the european crayfish species populations is decreasing. It is caused by unfavourable regulation of streams, water pollution and the occurence of crayfish plague. The main purpose of present study was examining the impact of electrostimulation on the males of the crayfish and obtaining sex products (the sperm). The principle of this research was determining whether the male of crayfish are able to extrude spermatophore with sperm by an electric stimulus. The transformer was used as resource alternating current in experiments. All experiments conducted in a laboratory of experimental device for fish farming in Vodňany. Experiments were conducted in 2011 on a male of the spiny-cheek crayfish (Orconectes limosus), the signal crayfish (Pacifastacus leniusculus) and the red swamp crayfish (Procambarus clarkii). The results of this work and success of the experiments suggest, that electrostimulation could be used for obtaining sex products (the sperm) from crayfish males. Results from a laboratory of electron microscopy confirm the harmlessness of electrostimulation on the shape and structure of sperm. The sperm can be used to artifical insemination of the crayfish eggs in future. However, sperm capacitation is problematic.
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Cryoconservation of fish sperm in model species - common carp (Cyprinus carpio): the influence of different temperature regimes of cryopreservation on the viability of thawed spermatozoa.
SOCHOROVÁ, Denisa
Influence of temperature and freezing rate on sperm survival after thawing were objective of this study. Motility (percentage of moving sperm), velocity and duration of sperm movement before and after process of freezing were observed in common carp (Cyprinus carpio L.) spermatozoa. Solutions recommended by Kopeika (1986) and Kurokura (1984) were used as a cryoprotective media. Sperm freezing was performed in 0.5 ml straws layed in styrofoam box 3, 6 and 9 cm above the level of liquid nitrogen for 20 min. Temperature changes during process of freezing were recorded inside and outside straws using thermocouple thermometer with miniature probes T type (cuprum ? constantan). At a fi rst level (corresponding to height 3 cm above level of liquid nitrogen) we recorded lowest temperature -170 °C, on a second (6 cm) -110 °C and on a third level (9 cm) -70 °C. Best results of sperm motility after freezing ? thawing were achieved using Kopeika solution and freezing at first level (3 cm above liquid nitrogen) where we reported 27 % of motile spermatozoa and velocity of movement 118 ?m.s-1. Freezing by Kurokura solution resulted in motility 14 % and velocity 76 ?m.s-1 whereas motility of native sperm was 88 % and velocity 136 ?m.s-1.
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Psychosocial problems of infertility verbaled by patients of fertility treatment ambulance.
DVOŘÁKOVÁ, Alena
Infertility is the inability to naturally conceive a child or to carry a pregnancy to full term. There are many reasons why a couple may not be able to conceive, or may not be able to conceive without medical assistance. Infertility may have profound psychological effects. Partners may become more anxious to conceive. Marital discord often develops in infertile couples, especially when they are under pressure to make medical decisions. Women trying to conceive often have clinical depression. Even couples undertaking IVF face considerable stress, especially the female partner. In vitro fertilisation (IVF) is a technique in which egg cells are fertilised by sperm outside the woman's womb. IVF is a major treatment in infertility when other methods of achieving conception have failed. The process involves hormonally controlling the ovulatory process, removing eggs from the woman's ovaries and letting sperm fertilise them in a fluid medium. The fertilised egg (zygote) is then transferred to the patient's uterus with the intent to establish a successful pregnancy. In this study ten couples using fertility treatment were analysed. The purpose of this study was to follow and describe their problems during the treatment, troubles with partners, jobs and friends. The author tried to find a solution how to communicate with patients, how to help them to manage the treatment. The elected experimental strategy was qualitative analysis. This study could be used by stuff in centres of artificial reproduction.
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