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Genes of early meiotic prophase I of spermatogenesis in house mouse
Škaloudová, Eliška ; Trachtulec, Zdeněk (advisor) ; Forman, Martin (referee)
Meiosis is an essential cellular process that is necessary for gamete formation in all sexually reproducing organisms. This work is focused on the description of the genes of early stages of meiotic division in males of a mammalian model, the house mouse. The first part summarizes meiosis focusing on prophase I, which is longer than prophase II. Prophase I is divided into five stages, namely leptotene, zygotene, pachytene, diplotene, and diakinesis. Mouse spermatogenesis and its differences from oogenesis are also briefly described. The second part provides a list of genes encoding proteins required for initiation of meiotic division, pairing and synapses of chromosomes, and initiation of the catalysis of double-strand breaks. Double-strand breaks are repaired by homologous recombination, which may result in so-called crossing-over, the major source of genetic variability. The work deals with the early stage of homologous recombination and components required for this process. Localization of meiotic double-strand breaks in the genome is not random and is under the control of the Prdm9 gene, which seems to take multiple roles, such as the formation of new subspecies of the house mouse. Knowledge of the genes controlling the early stages of meiotic division is a prerequisite to understanding some of...
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Mechanisms of origin of cryptic rearrangements in human chromosomes and its clinical associations
Šenkyřík, Pavel ; Šolc, Roman (advisor) ; Drábová, Jana (referee)
Chromosomal rearrangements are one of the processes which leads to formation of genetic disorders. Among the mechanisms that cause the rearrangements belong NAHR, NHEJ, FoSTeS and MMBIR. They generate rearrangements of many types and have different requirements for their realization. NAHR is recombination-based mechanism responsible for recurrent rearrangements and operates mainly in repetitive sequences. NHEJ is used for repair of double-strand breaks and generates non-recurrent rearrangements due to its error rate. FoSTeS and MMBIR are replication-based mechanisms able to make both complex rearrangements and less massive non-recurrent rearrangements. Architecture of DNA has influence on all above-mentioned mechanisms. Structures that affect course or effectivity of mechanisms are microhomologies, double-strand breaks, tandem repetitions, hairpins, and loops causing stalling of replication fork.
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The role of methylation of histone 3 on lysine 4 (H3K4) during mouse spermatogenesis
Blumenstein, Jan ; Trachtulec, Zdeněk (advisor) ; Král, Jiří (referee)
Epige eti ké odifika e hro ati u hrají z ač ou roli v regula i přístup osti DNA. odifika í je etyla e histo ů. V H a lysi u ěhe sper atoge eze yši do á í a to zej é a ve Běhe eioti ké profáze I do hází k hro ozo ů, a k eioti ké reko i a i. Tyto pro esy jsou kriti ký ode tvor y pohlav í h u ěk a jeji h selhá í vede k eioti ké zástavě a tí páde k poruše tvor y haploid í h u ěk. Histo ová etyltra sferáza PRDM9 hraje klíčovou roli v eioti ké reko i a e, e oť je zodpověd á za urče í progra ova ý h dvouřetěz ový h zlo ů v íste h zva ý h hotspoty. Ni é ě ge je důležitý i ve spe ia i, a to řed i tví fe o é u hy rid í sterility. Další i protei y, které se podílí a etyla i histo u H a lysi u ěhe sper atoge eze, jsou MLL KMT D , MLL KMT E a yší h varlate h ovše az ačují, že regula i této odifika e hro ati u podílí ví e ge ů. Avšak ejsou z á é ko krét í fu k e, které ají tyto z ývají í ge y ěhe vývoje sa čí h pohlav í h u ěk. Další zkou á í tě hto ge ů ohou ýt užiteč á pro o jas ě í částeč é e o úpl é eplod os Klíčová slova: eioti ká reko i a e, dvouřetěz ové zlo y, hy rid í sterilita, sper atoge eze, etyla e histo ů
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Genes of early meiotic prophase I of spermatogenesis in house mouse
Škaloudová, Eliška ; Trachtulec, Zdeněk (advisor) ; Forman, Martin (referee)
Meiosis is an essential cellular process that is necessary for gamete formation in all sexually reproducing organisms. This work is focused on the description of the genes of early stages of meiotic division in males of a mammalian model, the house mouse. The first part summarizes meiosis focusing on prophase I, which is longer than prophase II. Prophase I is divided into five stages, namely leptotene, zygotene, pachytene, diplotene, and diakinesis. Mouse spermatogenesis and its differences from oogenesis are also briefly described. The second part provides a list of genes encoding proteins required for initiation of meiotic division, pairing and synapses of chromosomes, and initiation of the catalysis of double-strand breaks. Double-strand breaks are repaired by homologous recombination, which may result in so-called crossing-over, the major source of genetic variability. The work deals with the early stage of homologous recombination and components required for this process. Localization of meiotic double-strand breaks in the genome is not random and is under the control of the Prdm9 gene, which seems to take multiple roles, such as the formation of new subspecies of the house mouse. Knowledge of the genes controlling the early stages of meiotic division is a prerequisite to understanding some of...
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