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The effect of diabetes mellitus on male reproduction
Valášková, Eliška ; Pěknicová, Jana (advisor) ; Seifertová, Eva (referee)
Increasing infertility is considered a serious problem of human reproduction. Male factor infertility is the cause of more than 60% of problem pairs and sperm quality by reducing the number will grow. One of the possible risk factors is diabetes mellitus (DM). As a result of insufficient and often conflicting analyzes of sperm quality, the DM as a risk factor in the evaluation of male fertility neglected. The use of new molecular techniques revealed pathological effects diabetes mellitus on sperm function and spermatogenesis.
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Study of differential potential of spermatogonial stem cells via transplantation in vertebrates
Kodedová, Barbora ; Krylov, Vladimír (advisor) ; Pšenička, Martin (referee)
Spermatogonia, or spermatogonial stem cells are necessary to maintain male fertility. In the complex process of ongoing spermatogenesis in the testes these pluripotent stem cells proliferate and differentiate into sperm cells. In 1994 the first spermatogonial transplantation technique was described in rodents to allow the study of male germ cells. The following series of studies of intra- and inter-species transmission of testicular tissue revealed the regenerative capacity of transplanted spermatogonial stem cells and their possible usage. Recently, spermatogonia transplantation systems are developed in many vertebrates making it possible to study the development of sperm as well as artificial production of male and female gametes derived from germ cell donors. The differentiation potential of spermatogonial stem cells enabled the creation of transgenic organisms by genetic manipulation of isolated spermatogonia and subsequent transplantation into a suitable recipient. Spermatogonial transplantation in the future may find their application in regenerative medicine, the treatment of disorders of spermatogenesis, or serve to preservation of genetic stock of endangered species.
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Meiotic sex chromosome inactivation within mouse spermatogenesis
Homolka, David ; Jansa, Petr (advisor) ; Kubelka, Michal (referee) ; Pěknicová, Jana (referee)
Meiotic sex chromosome inactivation (MSCI) is an essential epigenetic process, which transcriptionally silences X and Y chromosomes during spermatogenesis. It is accompanied by substantial chromatin remodeling resulting in a formation of so called sex or XY body, which is a characteristic of male pachytene spermatocytes. In spite of MSCI indispensability for male fertility, its biological role and molecular nature still remain rather unclear. However, the described link between chromosomal asynapsis and transcriptional silencing demonstrated that MSCI is tightly associated with the asynapsis of largely non-homologous sex chromosomes and is a specific form of more general mechanism called meiotic silencing of unsynapsed chromatin (MSUC). The essential role of MSCI was demonstrated using mouse models, such as carriers of X- autosome translocations, where anomalous synapsis of sex chromosomes leads to impairment of MSCI and male sterility. Intriguingly, the exclusive spermatogenic arrest is a hallmark of not only X-autosome translocations but even various autosomal rearrangements, including autosomal translocations, inversions, or other structural mutations. Because the rearranged autosomes often intimately associate with the sex body, it...
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Effect of zearalenone on reproductive parameters and the expression of selected genes in mice.
Dvořáková, Eva ; Pěknicová, Jana (advisor) ; Nedvídek, Josef (referee)
A number of chemicals may have a negative impact on the environment and wildlife. Endocrine disruptors (EDs), which can mimic estrogen, interfere with natural hormones in organism and can have a negative effect on the reproductive system. Such substances include zearalenone (ZEA) - mycotoxin, produced by the fungi Fusarium. Despite the non-steriodal structure of its molecule, ZEA and its derivates possess potent estrogenic activity. The influence of ZEA on reproductive parameters and changes in expression of selected genes were tested in the outbred line of mice. This study showed significant effects of ZEA on number of reproductive performances. This effect was observed at lower examined dose, to which are humans normally exposed, and at higher doses, both showed changes in the tested parameters.
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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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Vliv antioxidantů (selen, vitamin C a E) na spermatogenezi kanců
Svačinová, Lucie
The purpose of this dissertation is the verification of antioxidants, the vitamin C, the vitamin E and selen influence on the spermgenesis of breeding boars. The ejaculate quality was evaluated with the use of qualitative and quantitative figures (the ejaculate volume, the motility, the sperm concentration and the number of abnormal sperms). The experiment was done at the boars' insemination station (ISK) in Velké Meziříčí. In the experimet, there were 12 boars of DUROC race involved. The boars were split into two groups. By the first boars experimental group (n=6) there were added into the feeding batch 350 mg of the vitamín C (ascorbe acid); 70 mg of the vitamín E (alfatocoferol) and 0,5 mg of selen (selenomethionin) per one kilogram of this special diet. The second group of boars was used as the checking group and the volume of the vitamin C, the vitamin E and the selen was not increased in their diet. The experiment was running for 90 days (June -- August). At the checking group the volume of their ejaculate was increasing untill the 60th day of the experiment, in the final stage it has significantly dropped, totally by -19%. By the experimental group, the volume of the ejaculate was constantly increasing trend and the total volume increase during the experiment duration was +32%. The sperm motility at the checking group has decreased from the original 69% down to 54%, while at the experimental group it has increased by approximatelly 1%. The sperm concentration check -- by the checking group it has increased by +6% and by the experimental group the sperm concentration has decreased by -24%. The number of abnormal sperms at the checking group has increased by +1% and by the experimental group the number of pathologic sperms has increased by +30%. Based on our results it is possible to say, that selen, the vitamin C and vitamin E do not have a provable effect on the boars ejaculate quality. But we must také into the consideration also the summer season, during which the experiment was provided. There were higher temperatures affecting the animals, which could have negative influence on the results.
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Spermatogenesis in long lived species of water bugs ? water cricket (Velia caprai) (Heteroptera: Gerromorpha: Veliidae)
BĚLINOVÁ, Lucie
This diploma thesis is devoted to the spermatogenesis of long living water bug species ?water cricket (Velia caprai). Spermatogenesis of nymphs of the fifth instaru, adults of defined age (from 1 up to 60 days after the ecdysis) and also the adults caught in the field of unknown age before - and after the hibernation were studied by histological methods. It was discovered that spermatogenesis of this species is in progress continuously. Even the nymphs of the 5th instar already had spermatids presented and the adult males disposed of spermatozoans just one day after the ecdysis. The presence of all the spermatogenesis cell types (spermatogonia, primary and secondary spermatocytes, spermatids and sperms) was confirmed in the case of male adults of various age ? younger after ecdysis as well as older including males after hibernation. Semiaquatic bug Velia caprai has not typical testes in comparison with most of Insects. They are formed by just one testicular follicle which is wider than longer. The follicle´s top is not distinctly formed; the germanium is located in the middle of the follicle´s wider part which is across from the testicle´s orifice to vas deferens. This anomalous position of germarium represents the original apex of testicular follicle in this species.
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