National Repository of Grey Literature 17 records found  1 - 10next  jump to record: Search took 0.00 seconds. 
Recombination hot-spots in various organisms
Stočesová, Lucie ; Holá, Dana (advisor) ; Forman, Martin (referee)
Meiotic recombination is an important process which occurs in sexually reproducing organisms and creates new allelic combinations. Frequency and distribution of crossing-overs (COs) are affected by many internal and external factors. Regions with higher frequency of COs are called recombination hot-spots and in this thesis, they are divided into ancestral and derived hot-spots. Ancestral hot-spots are the more original ones and they are determined by histone modifications, nucleosome-depleted regions, promoters and sequence motifs. This type of hot-spots occurs, e.g., in yeasts, birds and plants. Derived hot-spots are determined by the PRDM9 protein, which searches for specific sequence motifs and creates histone modifications. These hot-spots are typical for most mammals except the canines which lost functional PRDM9 due to the mutation of the Prdm9 gene. Activity of PRDM9 destroys primary locations of hot- spots via gene conversion. This process is called "hot-spot paradox" and is solved by the rapid evolution of alleles of the Prdm9 gene. This thesis summarizes basic information on distribution and determination of hot-spots among various eukaryotes. It particularly focuses on the PRDM9 protein, its structure, function and evolution. A determination of location of recombination in species...
Robertsonian translocations and their involvement into genome evolution
Mlnáříková, Barbora ; Forman, Martin (advisor) ; Sember, Alexandr (referee)
Chromosome aberrations play an important role in human pathologenesis as well as in evolution of many organisms. Robertsonian translocation or centric fusion are the most frequent chromosomal rearrangements in mammals. The most investigated model for their research is house mouse Mus musculus. The standard karyotype of a mouse consists from 40 acrocentric chromosomes, notably there are more than one hundred wild populations that are characterized by various combination of metacentrics, formed by centric fusion of different acrocentrics. Several models have been proposed for the formation of metacentrics, taking account of the sequential structure of their centromeres and short arms in mouse. Segregation distortion in favor of metacentrics is present in female and/or male meiosis, such as meiotic drive can positively affect the degree of fixation of metacentric chromosomes in certain population. Centric fusions have been also presented in evolution of other organisms. Cytogenetic data in spiders indicate the possibility of similar phenomena in the most diversified group of spiders, Entelegynae. Spiders are notable for their unusual sex chromosome systems. Centric fusions also play an important role in the evolution of sex chromosomes and the formation of neo-sex chromosome systems. So far, there is...
Mechanisms of chromosome rearrangements and their relation to the formation of polyploid species
Vaňková, Tereza ; Knytl, Martin (advisor) ; Forman, Martin (referee)
Polyploid species are significantly represented among plants and some animals. Whole- genome duplication (WGD) is an unstable process with rapid changes in a genome and also changes in chromosomes. These changes includes chromosomal aberrations, such as translocations, duplications, insertion and inversions. Chromosomal aberrations and WGD are strongly represented in the evolution of organisms. Therefore the study of their mechanisms is important for an understanding of genomic development. At present, there are developments in cytogenetic technique helping study polypoid genomes and also helping add polyplodozation events to evolutionary contexts. These techniques includes banding as well as fluorescent in situ hybridization, which, thanks to the applicability of various probes, helps to detected chromosomal rearrangements. Keywords: Chromosome rearrangements, polyploid, WGD, cytogenetic techniques, FISH
Analysis of concentration, ownership structure and integration tendencies of breweries in Czechia
Forman, Martin ; Květoň, Viktor (advisor) ; Slach, Ondřej (referee)
Over the last ten years the phenomenon of opening new microbreweries has reached Czechia. Since 2008 more than 350 new microbreweries have been opened and the map of breweries has recorded significant changes. Regarding these facts the main goals of this thesis were to analyze the brewing industry in Czechia in the context of ownership structure, concentration tendencies and mergers and acquisitions activity. First part focuses on the characteristics of the breweries' geographical layout related to the ownership structure and size based on annual beer production and in context of selected socioeconomic indicators. Following this part is an analysis of decomposition with use of concentration and cluster ratios. This part aims on cluster forming tendencies of brewing companies. The analytical part is completed with mergers and acquisitions characteristics in this industry sector. The basic figures and signs of the geographical decompositions were identified based on selected analytical methods and complex maps. Several concentration zones where breweries tend to cluster were labeled using the cluster analysis. Mergers and acquisitions reveal the difference in integration activity according to the brewery size. Key words: brewing industry, breweries, ownership structure, concentration, cluster, Czechia
Mechanisms of chromosomal rearrangements in the context of polyploid species and its forming
Vaňková, Tereza ; Knytl, Martin (advisor) ; Forman, Martin (referee)
Polyploid species are significantly represented among plants and some animals. Whole- genome duplication (WGD) is an unstable process with rapid changes in a genome and also changes in chromosomes. These changes includes chromosomal aberrations, such as translocations, duplications, insertion and inversions. Chromosomal aberrations and WGD are strongly represented in the evolution of organisms. Therefore the study of their mechanisms is important for an understanding of genomic development. At present, there are developments in technique helping study polypoid genomes and also helping add polyplodozation events to evolutionary contexts. These techniques includes banding as well as fluorescent in situ hybridization, which, thanks to the applicability of various probes, helps to detected chromosomal rearrangements.
Avian polyomaviruses
Škvára, Petr ; Fraiberk, Martin (advisor) ; Forman, Martin (referee)
Avian polyomaviruses are small, nonenveloped viruses from family Polyomaviridae, which can cause acute infection with high mortality of infected birds. In contrast with other polyomaviruses, avian polyomaviruses do not share similar pathogenesis, because most of them do not cause acute diseases. The main point of this work is to summarize available information about avian polyomaviruses and to compare them to each other. This work also compares avian polyomaviruses with mammalian polyomaviruses. The primary focus is made on genome organization, structure and function of viral proteins, but also on pathogenesis and epidemiology of avian polyomaviruses. In conclusion, even if avian polyomaviruses share common signs with other polyomaviruses, they have different conserved sequences, host specificity and pathogenicity. Summary of current knowledge about avian polyomaviruses could help to understand the importance of this newly established genus in the field of polyomavirus research. Key words: avian polyomaviruses, taxonomy, genome, viral proteins, pathogenesis
Heterochromatin variants of the human karyotype
Michalová, Michaela ; Šípek, Antonín (advisor) ; Forman, Martin (referee)
Chromosomes are cell structures consist of chromatin, out of which one kind is a constitutive heterochromatin, which contains non-coding sequences only and is transcriptionally inactive. Heterochromatin blocks consist of highly repetitive sequences of satellite DNAs, which allows the parts to be variable. The largest areas of heterochromatin can be found at long arms of chromosomes 1, 9, 16 and Y, but heterochromatin areas also affect the variability of the short arms of acrocentric chromosomes 13 - 15, 21 and 22. This bachelor thesis based on a number of scientific essays summarizes findings about heterochromatic variants, their occurrence, frequency, possibilities of examining as well as their clinical significance in today's world. It mainly highlights their possible connection with reproductive failures and contradictory results of individual observations. Contemporary results show the importance of new laboratory methods (molecularly cytogenetic), which can be used in specifying and more detailed sorting of findings, which were previously tagged as harmless variants according to less accurate banding methods. The summarization implies that emphasis should be put on the study of clinical meaning of heterochromatic variations. These can influence the progress of meiosis and thus trigger...
Karyotype evolution of the Dictyoptera group
Jankásek, Marek ; Šťáhlavský, František (advisor) ; Forman, Martin (referee)
Diploidní počty chromosomů a komentář k jejich morfologii pro 107 druhů řádu Mantodea ♂ - , 126 druhů skupiny "Blattaria" ♂ - a 84 druhů skupiny Isoptera ♂ - této bakalářské práci s meiotickému dělení a chromosomovým mechanismem určení pohlaví. Pozornost byla také dána některým zvláštním prvkům karyotypu skupiny Dictyoptera jako je premetafázní protažení a formace rozličných chromosomálních multivalentů. Celková informace o karyotypech skupiny Dictyoptera je vztažena k řádu Mantodea, principy karyotypových změn napříč evolucí některých nově definovaných skupin mohly být navrženy. Ve skupině "Blattaria" není možné utvářet jakékoliv širší úsudky o karyotypové evoluci, jelikož většina cytogeneticky studovaných druhů je z čeledí "Ectobiidae" a Blaberidae, pro které stále chybí detailnější fylogenetická studie. Některé evoluční trendy mohly být vyneseny ve skupině Isoptera, jakožto formace rozličných chromosomových sexuálních multivalentů a častá fúze jednoramenných chromosomů. Klíčová slova:
Molecular mechanisms of G2/M checkpoint regulation
Kořínková, Klára ; Macůrek, Libor (advisor) ; Forman, Martin (referee)
Cell division is necessary for maintaining tissue homoeostasis, but at the same time its defects are closely related to the development of many diseases including cancer and premature ageing. Activation of oncogenes leads to replication stress and directly threatens genome stability. The right control of transition between interphase and mitosis is an important mechanism for the protection of genome integrity. Nuclear division is only possible with those cells in which flawless duplication of genetic information occurred. By contrast, cells with damaged DNA structure remain temporarily or permanently stopped at G2 phase of the cell cycle. The topic of this thesis is a detailed literature overview with the subject of molecular mechanisms of the G2/M transition regulation under unperturbed conditions and in the presence of damaged DNA.

National Repository of Grey Literature : 17 records found   1 - 10next  jump to record:
See also: similar author names
2 Forman, Michael
1 Forman, Mikuláš
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