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Detection of positive selection in reproductive genes of songbirds
Cakl, Lukáš ; Reifová, Radka (advisor) ; Těšický, Martin (referee)
Reproductive genes are assumed to play an important role in adaptive evolution and speciation, yet little is known about the patterns of molecular evolution in these genes within avian species. This thesis is focused on identifying reproductive genes under positive selection and analyzing their function in songbirds, the largest and most diverse suborder of modern birds. Using existing bioinformatic approaches and published genomic data of 14 songbird species, we have first constructed 12000 groups of orthologous genes and detected significant traces of recurrent positive selection within 385 of them. Using proteomic data, this genome wide set of genes was then filtered to obtain genes expressed within songbird spermatozoa and fluids from the female reproductive tract. Within spermatozoa 22 out of 940 expressed genes were positively selected, while female fluids were found to be more conserved, as only 6 out of 529 expressed genes have shown traces of positive selection. We have then computed the enrichment of gene ontology terms within the positively selected genes. The enriched terms suggest evolutionary pres- sures acting on spermatozoa cytoskeleton, molecular motors and energetic metabolism, highlighting the importance of sperm morphology and swimming speed. Furthermore, the enrichment results...
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Význam vitaminu D a jeho metabolitů v reprodukci živočišných organismů
Červenka, Jiří
Vitamin D is considered to be a group of molecules that have many functions in animal organisms. The best known of these is the key role in calcium and phosphorus homeostasis and regulation of bone mineralization. In recent years, however, many new functions of this vitamin have been discovered, such as the regulation of cell proliferation and differentiation, its influence on the immune system or its function in animal reproduction. This thesis deals with the importance of vitamin D in animal reproduction with an emphasis on livestock. In the literature review, the occurrence of receptors for vitamin D in cells of various types of different tissues of reproductive system, particularly in mammals and birds, and the function of various metabolites mediated by these receptors are discussed in the individual chapters. The thesis includes the design of methodology, which would test the effect of vitamin D on reproduction of the male and female domestic chickens. The hypothesis could verify, whether or not, Rhode Island Red cockerels, that would be fed a diet with a higher vitamin D content would demonstrate better ejaculate parameters and higher fertilization of eggs laid by Rhoade Island White hens inseminated with this semen. Furthemore, a solution is proposed to verify the hypothesis, assuming higher hatchability and lower embryonic mortality in hens fed higher vitamin D feed mixture. The result would be compared with hens and roosters of the same breeds, reared in an environment with the same conditions, fed a vitamin D deficient feed mixture.
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Post-Translational Modifications of Nuclear and Non-Nuclear Proteins in Spermatozoa
Řimnáčová, Hedvika ; Nevoral, Jan (advisor) ; Krapf, Dario (referee) ; Álvarez Rodríguez, Manuel (referee)
Posttranslational modifications of nuclear and nonnuclear proteins in spermatozoa Summary The number of couples who need the help of assisted reproductive technology (ART) has increased over the years. Approximately half of the cases are caused by male infertility, which is often diagnosed as idiopathic infertility. Therefore, the search for male fertility markers will improve male infertility diagnosis, thereby facilitating advanced sperm treatment and selection via ART. Posttranslational modifications (PTMs) of sperm nuclear and nonnuclear proteins are suitable candidates for such markers. The PTMs of protamines and histones reflect sperm chromatin maturity and its readiness for fertilization, and accordingly, they can predict the outcome of ART. However, the PTMs of nonnuclear proteins, including cytoplasmic, cytoskeletal, and membrane proteins, reflect the ability of sperm to undergo hyperactivation, capacitation, or acrosome reactions, which are processes essential for fertilization. We hypothesize that the PTMs of nuclear and nonnuclear proteins can reflect sperm quality and, thus, serve as a valuable marker in ART. Additionally, we suggest that the in vitro addition of hydrogen sulfide into the sperm-manipulating media improves sperm motility and viability via persulfidation. We used Western blot...
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Glycoprotein profile of human ejaculate as a marker of its quality
Pavlová, Hana ; Postlerová, Pavla (advisor) ; Krejčová, Tereza (referee)
Glycoproteins are an indispensable component of the sperm glycocalyx. They arise through the process of co-translational or post-translational modification, so-called glycosylation, during which carbohydrate chains are attached to a peptide chain. Glycoproteins are involved in reproductive processes and their presence is often key to successful fertilization. The degree of glycosylation of glycoproteins is highly variable and is determined by the representation of carbohydrate units in glycans. It has already been found that the degree of glycosylation can be related to the fertility of an individual. The diploma thesis is focused on the comparison of the representation of terminal saccharides, sialic acid and fucose, in the glycoproteins of sperm and seminal plasma of patients with normal and abnormal ejaculate parameters. The total rate of sialylation and fucosylation in the seminal plasma was determined, as well as the rate of sialylation and fucosylation of specifically detected glycoproteins of sperm and seminal plasma. A significant difference was noted only in the detection of total fucosylation of seminal plasma glycoproteins. However, subsequent correlation tests revealed important relationship between the degree of sialylation and fucosylation of glycoproteins and ejaculate parameters,...
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Physiological and hormonal mechanisms influencing ejaculate quality in birds
Mojžišová, Kateřina ; Tomášek, Oldřich (advisor) ; Svobodová, Jana (referee)
Sexual selection is an important mechanism of evolution. In addition to precopulatory sexual selection, arising when males compete for female partners, there is also postcopulatory sexual selection (sperm competition), when females copulate with more males. Even though most avian species are socially monogamous, most of them are also partially promiscuous. In such species, sperm competition is an important factor increasing variability in reproductive success between males. Male's success in sperm competition is primarily determined by sperm concentration, total sperm count and morphology and motility of spermatozoa. My bachelor thesis summarizes knowledge about the hormonal a physiological mechanisms that influence semen quality. This is especially the effect of sex and other hormones, physiological and oxidative stress, environmental conditions, antioxidant mechanism and composition of sperm cell membrane. Besides evaluating their influence on ejaculate quality on intraspecific level, I also describe their differences between avian species with respect to the differences of sperm competition.
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Meiosis and fertility of juvenile mouse males
Valtrová, Pavlína ; Trachtulec, Zdeněk (advisor) ; Reifová, Radka (referee)
This work is a summary of literature on pecularities of spermatogenesis in juvenile mouse males (Mus musculus) and their utilization. Spermatogenesis is a process that leads through meiosis to sperm production. The cell undergoes in waves the following cell types: spermatogonia, spermatocytes, spermatids, and spermatozoa. Juvenile mice (whose testes size and sperm count have not reached their maximum) are often used to study individual cell types. The transition between cell types takes shorter time in juveniles. Spermatozoa from the 1st wave of spermatogenesis (WS) are derived from prenatal gonocytes, allowing earlier sperm production. They have a lower frequency of crossing over (CO rate) due to a different processing of CO intermediates; the consequence can be aneuploidy (one chromosome less/more). Spermatozoa from the 2nd WS still display lower CO rate. In 3rd WS testes descend and their temperature decreases to 33řC; CO rate is more like in adults. In 4th WS is typical testicular supportive cells mature and CO rate is similar to adult levels. Juvenile males also suffer from more frequent and severe sperm malformations. Low CO rate should not have an impact on fertility; errors are eliminated during meiotic checkpoints. However, the children of young fathers have a higher risk of aneuploidy,...
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Epigenetic and structural characteristics of mammalian oocytes and embryos: extrapolation for human ART
Langerová, Alena ; Fulka, Josef (advisor) ; Pěknicová, Jana (referee) ; Chod, Jiří (referee)
It is now more than 35 years since the first world test-tube baby, Louise Brown, was born (1978) in England and it is estimated that since then more than 4 000 000 of children were produced by in vitro fertilization (IVF) worldwide. The initial success of IVF was less than 20% in best clinics, but now it reaches about 40%. This is a consequence of introduction of new methods, standardization and exploitation of new manipulation and culture media, as well as the incorporation of research results. Nevertheless, the most important still remains the skill and experience of IVF clinics and IVF laboratories staff, especially their ability to critically evaluate the quality of biological material and to decide which cure and treatment are the best one. At least, some biological material (immature and low quality oocytes) can be used for training and also for some experiments aiming to explain some questions, which are not yet fully understood (for example aneuploidies in human oocytes and embryos). In addition, this training can facilitate the introduction of new progressive approaches and may also improve indirectly the quality of infertility treatments. The first part of thesis is focused on the quality evaluation of oocytes collected by aspiration from follicles of stimulated patients. For labeling...
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Physiological and hormonal mechanisms influencing ejaculate quality in birds
Mojžišová, Kateřina ; Tomášek, Oldřich (advisor) ; Svobodová, Jana (referee)
Sexual selection is an important mechanism of evolution. In addition to precopulatory sexual selection, arising when males compete for female partners, there is also postcopulatory sexual selection (sperm competition), when females copulate with more males. Even though most avian species are socially monogamous, most of them are also partially promiscuous. In such species, sperm competition is an important factor increasing variability in reproductive success between males. Male's success in sperm competition is primarily determined by sperm concentration, total sperm count and morphology and motility of spermatozoa. My bachelor thesis summarizes knowledge about the hormonal a physiological mechanisms that influence semen quality. This is especially the effect of sex and other hormones, physiological and oxidative stress, environmental conditions, antioxidant mechanism and composition of sperm cell membrane. Besides evaluating their influence on ejaculate quality on intraspecific level, I also describe their differences between avian species with respect to the differences of sperm competition.
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