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Sperm competition in humans
Vydarená, Eliška ; Havlíček, Jan (advisor) ; Tomášek, Oldřich (referee)
Sperm competition has been observed and studied many times in a lots of animal species. It is currently also being considered in humans. Despite the number of studies, most of them were mainly focused on insects and birds. So far, only a small number of studies have dealt with sperm competition research in humans. For this reason, the question if sperm competition appeared and had selection pressure for the creation of various adaptations even in human evolution remains a controversial topic. In this bachelor thesis, I summarize the current knowledge of sperm competition in humans, the frequency of extra-pair copulation and paternity, and in individual chapters to indicate what adaptations to sperm competition may have developed in humans during their development. Key words Sperm competition, human sexuality, sperm, reproductive strategies
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Gonadal development during the lifetime of the fastest maturing model vertebrate- turquoise killifish (Nothobrachius furzerí)
LANDOVÁ, Magdaléna
Turquoise killifish had to adapt to the inhospitable conditions in which they live, especially drying temporal water bodies, which means certain death. The life sprint of the representatives of this genus is at its peak within one-month post-hatching, when both sexes have fully developed gonads and can reproduce. This rate comes with a high cost, as the killifish gonads begin to show signs of tissue degradation and germ cell apoptosis as early as three months post-hatching. Germ cell loss increases with age. A description of the development and degradation of the gonads in males and their breeding was elaborated. For the evaluation of aging-specific changes, immunochemical methods were used, focusing on the binding of specific antibodies against target epitopes and their visualization using fluorescence microscopy. Procedures for histological specimens have also been described, both for classical light and fluorescence microscopy.
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Cambarellinae: Trpaslíci ve světě račích spermií?
TOMAN, Jan
Recently, the ultrastructure of crayfish spermatozoa has become an increasingly studied topic. Up to now, the ultrastructure has been studied and defined in about fifteen species of freshwater species from all four crayfish families, however it has not yet been studied in a group of dwarf crayfish (subfamily Cambarellinae). Present work aimed to describe the spermatozoa ultrastructure of two dwarf crayfish species, specifically the Orange dwarf crayfish Cambarellus patzcuarensis and the Texas dwarf crayfish C. texanus. These species were then compared with the species already studied using morphological traits and biometric data. The ultrastructure of their spermatozoa shows commonly known patterns that include the acrosome and subacrosome in the front and the nucleus on the opposite side of the cell . Furthermore, radial arms typical for the superfamily Astacoidea that wrap around the nucleus and the whole cell enclosed by the extracellular capsule. The results show that the size of the acrosomes of Parastacidae membres is the smallest, while the crayfish of the Astacidae family show the largest acrosome. The current study points out a medium-sized acrosome of dwarf crayfish and Cambaridae in general, although they are located at the lower margin of this family with the Brazos crayfish being close to representatives of the Parastacidae. In conclusion, it is important to say that the combination of the morphological traits and biometric data of sperm acrosomes allows distinguishing individual crayfish groups to a large extent. This study may help to identify other species that have not been studied so far and could be a valuable basis for subsequent research of the ultrastructure and biometrics of crayfish spermatozoa.
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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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LINC complex: The link between chromatin integrity and sperm motility
Šanovec, Ondřej ; Komrsková, Kateřina (advisor) ; Lánská, Eva (referee)
The LINC complex (Linker of the Nucleoskeleton and Cytoskeleton) is a protein structure located in the nuclear membrane that connects the cytoskeleton with the nucleoskeleton. This complex can be found in every mammalian cell including the gametes. However, here the LINC complex is more diverse and less studied than in the somatic cells. In this thesis, the LINC complex and its role in spermiogenesis have been studied in wild-type and Protamine 2 knockout (Prm2-/- ) mice. Protamines are small proteins that replace histones during spermiogenesis. The mouse model generated by the group of prof. Hubert Schorle has a deletion in Prm2 in exon 1 and its sperm possess a surprising phenotype including complete loss of motility. Therefore, it was hypothesized that the LINC complex might be responsible for miscommunication between the sperm head and tail which leads to the loss of sperm motility. Results from this study suggest that the LINC complex is not influenced by Prm2 deletion, however, actin dynamics, cytoskeletal motor proteins and tubulin acetylase/ histone deacetylase activity might be impaired. Prm2-/- sperm have a significantly higher abundance of β-actin compared to the wild type. Next, Prm2-/- sperm also show a different pattern of acetylation of α-tubulin but no change in the abundance of...
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Evolution of sperm morphology in birds
Zemanová, Aneta ; Stopka, Pavel (advisor) ; Frolíková, Michaela (referee)
The sperm is one of the most variable cells that carry various morphological differences across species and is subject to selective pressures that may drive changes in sperm morphology. Different morphological adaptations that emerged may enhance successful fertilization. This thesis focuses on the analysis of sperm morphology in different species of songbirds, the representation of proteins in both sperm and seminal fluid, and their classification into different categories of gene ontology. The main aim of my thesis was to determine whether differences in proteomes follow the level of sperm competition or rather their phylogeny. Six species of songbirds were selected for this study: Marsh Warbler (Acrocephalus palustris), White-throated dipper (Cinclus cinclus), European greenfinch (Chloris chloris), Barn swallow (Hirundo rustica), Common chiffchaff (Phylloscopus collybita) and Zebra finch (Taeniopygia guttata). Sperm morphometric measurements were made in all the species, with the greatest variability recorded in the central part of the sperm flagellum. Using mass spectrometry, were analysed sperm and seminal fluid proteins separately and discriminant analysis was performed to determine the proteins that most differentiated the selected songbird species from each other. Obtained data provide...
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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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Evaluation of antisperm antibodies (ASA) in diagnostics of idiopathic infertility
Pastyříková, Soňa ; Postlerová, Pavla (advisor) ; Novák, Jan (referee)
Infertility is a problem affecting almost 15% of couples. It can be caused by genetic, hormonal, anatomical or infectious problems, and it can also be caused by an immunological factor. One of the immunological causes of infertility is the presence of anti-sperm antibodies (ASA), which bind to sperm and adversely affect their function. The occurrence of ASA is manifested, for example, by reduced sperm motility, agglutination, and impaired sperm capacitation. Alternatively, ASA reduces the sperm ability to pass through the female urogenital tract, negatively affecting the sperm-oocyte interaction and the development of the embryo. The aim of this bachelor thesis was to compare existing methods for ASA determination. The main parameters were the complexity of the method and the assessment of results according to clinical studies focused on the detection and evaluation of ASA. The exact comparison of ASA detection methods based on the performed studies proved to be complicated, mainly due to the development of individual methods over time, different approaches to the evaluation of results, and low standardization of the methods. However, the most commonly recommended methods are MAR, ELISA and IBT tests, which are standardized and, due to commercially available kits, are considered to be easy to...
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Chemical communication of gametes
Otčenášková, Tereza ; Komrsková, Kateřina (advisor) ; Petr, Jaroslav (referee)
Fertilization is a multiple step process leading to fusion of female and male gametes resulting in a formation of a zygote. Besides direct gamete interaction via binding receptors localized on both oocyte and sperm surface, fertilization also involves communication based on chemical molecules triggering various signalling pathways. This work is aimed to characterize chemical communication of gametes of a model organism Mus musculus. For this purpose, modern proteomic and visualisation methods like nano-liquid chromatography tandem mass spectrometry (nLC-MS/MS), selected reaction monitoring (SRM) and immunofluorescent microscopy were used. Lipocalins were identified as candidate proteins involved in communication including those from major urinary proteins (MUPs), LCN lipocalins and fatty acid binding proteins (FABPs). For the first time, we report their presence in the sperm acrosome. Based on lipocalins capacity to bind and transport other molecules, we propose that these proteins have a protective and/or signalling role for gametes. Furthermore, chemical communication between sperm and oocyte is based on chemotaxis which enables their interaction before their fusion. In this work, we detected that spermatozoa show chemotactic responses in the presence of L-glutamate. This amino acid naturally...
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