National Repository of Grey Literature 51 records found  beginprevious22 - 31nextend  jump to record: Search took 0.00 seconds. 
Karyotype evolution of selected families of entelegyne spiders
Kotz, Matěj ; Král, Jiří (advisor) ; Nguyen, Petr (referee)
The Araneoidea superfamily is a diverse clade of spiders with a great species diversity. The whole superfamily displays considerable conservativeness of observed karyotypes. Most likely ancestral karyotype in males is 24 acrocentric chromosomes with X1X2 sex determination system. The goal of this study is to explore the karyotype diversity of two araneoid families - Araneidae and Mimetidae. The majority of studied species exhibit the ancestral karyotype. In some species of the aformentioned families was observed sudden increase in chromosome numbers, up to 2n♂ = 52 in Araneidae and up to 2n♂ = 57 in Mimetidae. The latter number is the highest chromosome count observed in Entelegynae so far. Increase in 2n goes hand in hand with increase in sex chromosome numbers, leading up to X1X2X3X40 system in Araneidae and up to X1X2X3X4X5X6X70 in Mimetidae. I suggest polyploidy as a possible mechanism of the increase. To test this hypothesis, I measured the size of the genome using flow cytometry and used fluorescence in situ hybridization for the detection of 18S rRNA and 5S rRNA genes. For one species, probe for U2 snRNA gene was also optimized as part of this thesis. In many species studied, these techniques were used for the first time ever. In the case of the family Mimetidae, the largest genomes in...
Evolution of sex chromosomes in reptiles
Mazzoleni, Sofia ; Rovatsos, Michail (advisor) ; Zrzavá, Magda (referee) ; Liehr, Thomas (referee)
- ABSTRACT - Among vertebrates, reptiles represent the ideal group for the study of sex determination. Reptiles include lineages with environmental sex determination (ESD) as seen in crocodiles and tuatara, lineages with genotypic sex determination (GSD), like e.g. iguanas, chameleons, skinks, lacertid lizards and birds, and few groups which possess variability in sex determination mechanisms, i.e. geckos, dragon lizards and turtles. This thesis is focused on the evolution of sex chromosomes and sex determination in turtles. The majority of turtle species exhibit ESD, which is considered the ancestral sex determination system of this group, while GSD either as male or female heterogamety evolved independently at least five times. We investigated the presence of sex chromosomes in representative species of turtles by cytogenetic analyses. The analyses included the reconstruction of karyotypes, distribution of constitutive heterochromatin (C-banding, methylation analysis) and repetitive elements (fluorescence in situ hybridization) and comparative genome hybridization (CGH), which often characterize the degenerated Y or W and can be helpful in the identification of "cryptic" sex chromosomes. We described XX/XY sex chromosomes in seven previously unstudied Australasian chelids (Pleurodira) from the genera...
Digital Image Preprocessing Of Mitotic Chromosomes
Jaroš, Luboš
The goal of this work is to develop a novel algorithm for chromosome detection to make the following analysis of human genome easier. The algorithm uses a multiphase detection based on the Otsu and active contour methods. The accuracy validation is tested on samples from the online BioImlab databases.
Analysis of sex chromosomes and gene clusters in selected mygalomorph and araneomorph spiders
Pappová, Michaela ; Král, Jiří (advisor) ; Johnson Pokorná, Martina (referee)
1 Abstract: The diploma thesis focuses on study of sex chromosomes evolution and repetitive organized genes of chosen mygalomorph and araneomorph spiders. Spiders are characterized by complexicity of sex chromosome systems, their karyotypes contain multiple sex chromosomes X. Besides multiple X chromosomes they also contain a pair or two pairs of nondiferentiated sex chromosomes X and Y. The used methods include methods of classical cytogenetics (preparation of chromosome slides, C-banding) and methods of molecular cytogenetics (fluorescent in situ hybridization and comparative genome hybridization). Complex sex systems were discovered in the studied Theraphosidae spiders. In Theraphosidae spiders Atropothele socotrana and Poecilotheria vittata neo-sex chromosomes were found. Analysis of molecular differentiation of sex chromosomes suggests low differentiation of Y chromosome in neo-sex chromosomes and pair of nondifferentiated sex chromosomes XY. In haplogyne spider Kukulcania aff. hibernalis (X1X2Y), the Y chromosome was significantly differentiated, male specific signal covered the whole chromosome. Detection of 18S rDNA showed that karyotypes of majority of analysed Theraphosidae spiders and haplogyne spiders contain low number (1 or 2) of nucleolar organizing regions localized terminally, which...
Optimization of Processes in Logistics with Visualization Support
Kršák, Martin ; Bidlo, Michal (referee) ; Křivka, Zbyněk (advisor)
The master thesis aims to design, implement, and compare algorithms that optimize processes in logistics, mainly in the planning phase. Heuristics and approximation genetic algorithms will find an near-optimal solution to NP-hard problem, such as the traveling salesman problem, with a delay less than several hours. The role of this algorithm is to plan an efficient route for garbage trucks that collect and distribute large-scale waste to waste yards in a specific city. The goal of the optimization is to minimize the shipping costs.
Karyotype analysis of mesothelid spiders
Prokopcová, Lenka ; Král, Jiří (advisor) ; Zrzavá, Magda (referee)
Cytogenetics of mesothelid spiders is largely unkown. The presented diploma thesis is focused on the karyotype evolution of these spiders. As it is the most basal group of spiders, the analysis of its cytogenetics can bring important data about ancestral spider karyotype. In the framework of my thesis, I analysed diploid chromosome numbers, chromosome morphology, meiotic division, sex chromosomes and the pattern of selected molecular markers that were detected by fluorescence in situ hybridization. According to my results, mesothelid spiders have a high number of chromosomes and the prevalence of monoarmed chromosomes. Unlike other spiders, mesothelids have little differentiated sex chromosomes. Key words: evolution, spider, chromosome, karyotype, fluorescence in situ hybridization, nucleolar organiser region, sex chromosomes
Genetic Algorithms
Masárová, Mária ; Zbořil, František (referee) ; Zbořil, František (advisor)
This thesis deals with genetic algorithm, their terminology and use. It describes various problems that can be solved by using genetic algorithms. Different algorithms of swarm intelligence are also presented in this thesis, while firefly algorithm also serves to compare the efficiency between it and genetic algorithm. The main task of this thesis is to perform experiments with three optimization tasks, namely, travelling salesman problem, boolean satisfiability problem and searching for extreme in function.
Molecular composition and ultrastructure of holokinetic chromosomes
Šejgunovová, Nikola ; Král, Jiří (advisor) ; Dalíková, Martina (referee)
Holokinetic chromosomes are a specific type of chromosomes which differentiate from standard (monocentric) chromosomes especially by a diffuse form of domain which binds microtubules (holocentromere). It is related to changes on an ultrastructural and molecular level. These changes are shown in modifications in mitotic and meiotic division and in evolution of karyotypes. Holokinetic chromosomes don't have a primary constriction with a localized centromere and therefore neither an inner centromere domain which would connect sister chromatids. Kinetochore structure of holokinetic chromosomes seems to be simpler than kinetochore structure of monocentric chromosomes. Kinetochore covers most of the surface of mitotic chromosomes. There have been described several variants of meiosis of holokinetic chromosomes which differentiate by position of kinetochore on chromosomes. On a molecular level holokinetic chromosomes differentiate from monocentric chromosomes by a distribution of proteins of a centromere-kinetochore complex, which cover most of the surfaces of mitotic and meiotic chromosomes. This applies, for example, to centromeric histone H3 (CENH3), whose amount and distribution changes during interphase and nuclear division, which is unique in comparison to monocentric chromosomes. The distribution...
Karyotype evolution of the family Araneidae
Pajpach, Filip ; Král, Jiří (advisor) ; Sember, Alexandr (referee)
Orb-weavers (Araneidae) are a diversified spider family comprising more than 3,100 species in more than 170 genera. Together with 13 other families, they con- stitute to superfamily Araneoidea. The presented thesis focuses on karyotype evo- lution of Araneidae, including its comparison with a related family Tetragnathidae. The results obtained from 19 araneid and four tetragnathid species confirm previ- ously postulated hypothesis that the ancestral karyotype of Araneoidea (including Araneidae) consists of 24 acrocentric chromosomes in males, including two acro- centric X chromosomes of system X1X20. However, there is a tendency of 2n decrease in some araneids due to centric fusions. In these cases, centric fusions affected most autosomes (and sometimes gonosomes as well); number of chromosome pairs de- creased from 11 to six. Three independent reduction events were detected in this thesis. Furthermore, pattern of nucleolar organizer regions (NORs) was studied in this thesis using fluorescent in situ hybridization, since data on evolution of this marker are scarce in spiders. Striking variability in NORs number was discovered, ranging from one to 13 loci. Remarkably, multiple centric fusions were always ac- companied by considerable increase of NORs number. In araneids and tetragnathids possessing...
Evolutionary algorithms
Bortel, Martin ; Karásek, Jan (referee) ; Lambertová, Petra (advisor)
Thesis describes main attributes and principles of Evolutionary and Genetic algorithms. Crossover, mutation and selection are described as well as termination options. There are examples of practical use of evolutionary and genetic algorithms. Optimization of distribution routes using PHP&MySQL and Google Maps API technologies.

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