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In vitro fertilization in horses
Müller, Filip ; Šušor, Andrej (advisor) ; Šimoník, Ondřej (referee)
Reproductive management in horse breeding increasingly relies on in vitro fertilization (IVF) techniques. This technology entails a complex process, including the acquisition of immature oocytes, their in vitro maturation, fertilization with sperm, and subsequent cultivation of the early embryo before transfer into a synchronized recipient. However, the success of equine IVF is influenced by various factors such as oocyte quality, sperm capacitation, and technical issues unique to this process, compared to other mammalian models. This bachelor's thesis aims to summarize and evaluate current knowledge on IVF of horse eggs, identify key factors influencing success, and describe current procedures for gamete preparation. By incorporating the latest IVF approaches and optimizing them, a higher success rate can be achieved. Key aspects for improving equine IVF include gamete collection and handling, in vitro oocyte maturation, sperm capacitation, and subsequent embryonic development.
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Endocrine disruptors and their impact on mammalian oocyte developmental competence
Štenglová, Anna ; Němcová, Lucie (advisor) ; Ješeta, Michal (referee)
Endocrine disruptors (EDs) are defined as substances of exogenous origin that disrupt endocrine system. EDs are found in significant amounts in the natural environment, plastic products and flame retardants, leading to unavoidable exposure. Due to their broad effects, several organizations/ conventions aim to regulate their presence in the natural environment and limit, or even eliminate their production. By entering the body, they negatively affect development, reproductive, nervous or immune systems of various animal classes through hormones. Modified hormonal levels are associated not only with fertility issues, but also with physiological abnormalities, osteoporosis, depression or metabolic diseases. EDs affect the female reproductive system through hormonal modifications of the HHG axis, which can lead to an earlier pubertal onset in some cases. Under the influence of EDs, impairments can also be observed in the process of steroidogenesis, development of follicles and oocytes, particularly through meiotic defects, which can lead to premature ovarian failure or infertility. Multiple chemicals disrupt the females reproductive system across several generations through epigenetic effects. This work summarizes knowledge about these ubiquitous substances and their impact on female reproductive...
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Early ontogeny of the cell's circadian clock
Knapová, Adéla ; Sumová, Alena (advisor) ; Vácha, Martin (referee)
This thesis focuses on the development and function of the circadian system, which regulates biological processes in the body according to the 24-hour cycle. The circadian system and its key components, including the suprachiasmatic nuclei of the hypothalamus and peripheral oscillators, are introduced. The molecular operation of the circadian clock, which is influenced by two loops, is also discussed. A major theme is the ontogeny of the circadian clock, which occurs autonomously during embryonic stem cell differentiation. This process is influenced by various factors such as ultradian rhythms of the segmentation clock and the influence of maternal factors. However, not all signals are essential for the development of these clocks, and especially their rhythms, as revealed by in vitro methods. Furthermore, the thesis discusses how the behaviour of embryonic stem cells differs from cells differentiated from them, and why the circadian clock is dysfunctional in these cells. The work provides a deeper understanding of the ontogeny of the circadian system, its rhythms, and its regulatory mechanisms - that is, when, where and under what circumstances the clock starts to form and "tick".
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X-ray computed tomography of mouse embryo
Šejnohová, Marie ; Walek, Petr (referee) ; Kolář, Radim (advisor)
The aim of this semestral thesis is to compare the possibilities of available micro-CT systems. Theoretic part of this thesis there deals with possibilities of staining soft tissues and embryos because of enhancement the contrast of micro-CT images. Here follows a description of sources X-ray and detectors of available micro-CT systems. In practice there was realized the staining of embryo in cooperation with Department of histology and embryology in Brno. Then followed a measuring on FSI in Brno, ČVUT in Prague and synchrotron Elettra in Italy. In semestral thesis are described of the thesis there are compared the micro-CT systems and results of measuring embryos by means of presented systems and results are compared.The best results were obtained on micro-CT in Brno, where X-ray tube and flat panel detector were used. This images were used for a segmentation of cartilage olfactory system by means of 3D region growing. From results they were created 3D models for comparison with a manually segmented model. A less accurate results were obtain with the semi-automatic segmentation but this method isn’t too time-consuming.
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The Case
Svobodová, Hana ; Šrek Bromová, Veronika (referee) ; Gabriel, Michal (advisor)
I assume huddled topic that I put into my past work as well as in final work. Casting my body, which is covered with feathers and create a cocoon of him, husk without the interior. Sculpture has two sides, the principle of duality, femininity and counterpart. Outer packaging evokes pleasant birdlike body surface and in the inner part aggressively squeeze ends of the wicks feathers.
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Automatic smoothing 3D models of cranial embryonic mouse cartilage
Kočendová, Kateřina ; Harabiš, Vratislav (referee) ; Jakubíček, Roman (advisor)
The focus of this thesis is the smoothing of manually segmented 3D models of mouse embryo craniofacial cartilege. During the process of manual segmentation, artefacts and other imperfections appear in the final models and need to be repaired. Firstly, manual segmentation is corrected using gradients and thresholding. Subsequent smoothing methods are constructed based on theoretical research. Algorithmizing is executed in the MATLAB environment. All the designed algorithms are then tested on selected models. Statistical evaluation is determined using the Srensen–Dice coefficient, where manually smoothened models cleared of all artefacts are used as the gold standard.
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Využití embryotransferu v moderní reprodukci dojeného skotu
Lužíková, Darina
Darina Lužíková, Use of embryo transfer in modern reproduction in dairy cattle The bachelor´s thesis is focused on the use of embryo transfer in moder reproduction in dairy cattle. The main subject of this work is transfer of embryos which are collected in the Netherlands from in vitro production and transfered to the Holstein recipients in the Czech Republic. In the theoretical part is the thesis focused on the methodology of embryo transfer using embryos obtained by the classical way of lavage, including the preparation of donors. This work also describes the most common time and hormonal schedules used in the Czech Republic. The methodology of in vitro embryo production and oocyte retrieval using the ovum pick-up method is also described. The practical part evaluates the results of embryo transfers from the particular farm from December 2018 to April 2021.
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Cell cycle regulation and genome integrity protection in the early mammalian embryos
Knoblochová, Lucie ; Drutovič, David (advisor) ; Carr, Antony M. (referee) ; Fulková, Helena (referee)
(English version) Infertility is a major health problem, as it affects one in every six people worldwide (Njagi et al., 2023). One of the major reasons for infertility are aneuploidies, additions or losses of an entire or partial chromosome during cell division. Aneuploidies thus negatively influence cellular processes and potentially lead to developmental problems or embryo loss. It has been thought for a long time that aneuploidies arise mostly during oocyte development, and these mechanisms have been well studied. However, recent evidence has shown that aneuploidies arise also de novo after fertilisation and during the early embryonic development; but the molecular mechanisms of these abnormalities still remains elusive. Aneuploidies often originate during cell cycle division from unrepaired DNA damage in mitosis. DNA damage is sensed by DNA damage response (DDR) signalling pathways, which slow down or arrest cell cycle progression until it is resolved. An essential DDR factor during typical cell cycle progression is checkpoint kinase 1 (CHK1). However, the role of DDR factors in the early embryos, and especially CHK1, have not been well studied. Early embryonic development is regulated by maternal factors stored in the oocyte until the transcription of the embryonic genome begins. To study...
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Criminal aspects of assisted reproduction
Paták, Milan ; Sovová, Olga (advisor) ; Císařová, Dagmar (referee)
The concept of assisted reproduction is widely discussed by both professional and lay public. New scientific discoveries in the fields of biology and medicine as well as the use of methods and procedures that enable the emergence of new life raise number of issues, not only the legal ones. The purpose of this thesis is to provide the comprehensive survey of criminal law relationships which may arise in the context of providing the assisted reproduction. The thesis examines whether the current legislation guarantees sufficient protection of relations, interests and values covered by the Criminal Code. Within the analysis of crimes the thesis deals with the need for criminal repression and gives proposals de lege ferenda. The thesis is composed of five chapters. The first chapter is subdivided into two parts. Part One defines the concept of assisted reproduction, describes the historical overview of the events that preceded the current interpretation of the concept and explicates basic medical terminology related to the chosen topic. Part Two presents the basic principles on which the Czech regulation is established and contains specification of the relevant sources of law. The second chapter briefly characterizes the criminal and medical law and clarifies their relationship. The third chapter deals with the...
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