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Archaeogenetics in frog's phylogenetics
Teliščaková, Martina ; Symonová, Radka (advisor) ; Majtánová, Zuzana (referee)
Key words: Archaeogenetics, palaeogenetics, molecular palaeontology, phylogeny of frog's, molecular evolution, Anura, zooarchaeology The first part of my thesis deals with archaeogenetic research issues. There are described history and important moments when the archaeogenetic mehtods were applied. It is concerned with options that archaeogenetics has and restrictions that limit its research. It also focuses on possibilities of contamination of fossil materials and aDNA degradation. You will be familiarized with its chemical properties and the second part of this work deals with molecular evolution of sequence DNA. A search follows this part. It describes archaeogenetics methods provided that they help to clarify the phylogenetics of lower vertebrates, especially the phylogeny of Frogs (Palaeobatrachus, Pipa). I pointed out the present state of knowledge of frog's archaeogentics using archaeological research findings.
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Out of Asia Minor into Danube Drainage: Phylogeography and colonisation pathways in the loach fish Cobitis strumicae
Majtánová, Zuzana ; Choleva, Lukáš (advisor) ; Reichard, Martin (referee)
The spiny loach Cobitis strumicae is a small bottom-dwelling freshwater fish whose progenitor colonised the Balkan Peninsula from the Near East through the Asia Minor. The current geographic distribution of C. strumicae forms a ring around the Stara Planina (Balkan mountains), inhabitting Danube Basin and coastal rivers of Black Sea and Aegean Sea. Using one marker of mitochondrial DNA (gene for cytochrom b) and one marker of nuclear DNA (S7 gene, first intron), we reconstructed the species distribution and phylogenetic relationship of 44 populations throughout C. strumicae distribution. We also analysed its sister species, C. punctilineata, which lives inside the distribution area of C. strumicae. Aplication of four phylogenetic approaches confirm the monophyly and species statut and endemicity of C. punctilineata, and, moreover, the evidence of secondary hybridization with C. strumicae was found. The network analysis using median-joining method showed deep divergence between the both species. Phylogenetic analyses for cyt b gene confirmed the monophyly of C. strumicae, with internal substructure into at least two well divided lineages, which suggests the process of local speciation. Phylogenetic analyses of S7 gene did not support the monophyly of C. strumicae. Instead, the two separated...
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Evolution of sex chromosomes and karyotypes in boas and pythons
Charvát, Tomáš ; Rovatsos, Michail (advisor) ; Majtánová, Zuzana (referee)
- ABSTRACT - Snakes (Serpentes) are a group of squamate reptiles (Squamata) that represents more than one third of the total reptile species diversity. Snake karyotype is generally conserved with the most common chromosome number of 36 (16 macro- and 20 microchromosomes) in diploid state. It is believed that this karyotype was also present in the common ancestor of all snakes. The majority of snake species belong to the group Caenophidia and share homologous ZW sex chromosomes. Snakes from the groups "Scolecophidia" and "Henophidia" have mostly poorly differentiated, homomorphic sex chromosomes, which made them impossible to distinguish from the autosomes in the past. These snakes were for many years assumed to have ZW sex chromosomes as well. However, recent studies demonstrated not only ZW but also two non- homologous XY sex chromosome systems in non-caenophidian snakes and thus the sex determination systems in snakes are much more variable than previously thought. In this thesis, eight species of henophidian snakes (representatives from the genera Eryx, Cylidrophis, Python and Tropidophis) and one caenophidian species (Ophiophagus hannah) were examined using conventional and molecular cytogenetic methods. However, sex chromosomes were not detected in the henophidian species, only in Ophiophagus hannah,...
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Evolution of sex chromosomes and karyotypes in snakes
Augstenová, Barbora ; Kratochvíl, Lukáš (advisor) ; Majtánová, Zuzana (referee)
Snakes (Serpentes) are a group of squamate reptiles (Squamata) including more than 3600 species. The vast majority of snakes are from the group Caenophidia, which includes approximately 90% of all extant snake species and represents the most studied lineage. Squamate reptiles are variable in sex determination and genome organisation, however, caenophidian snakes are quite stable in these respects. The typical - and probably ancestral - snake karyotype is composed of 36 chromosomes with 16 macro- and 20 microchromosomes. In all snake species, genotypic sex determination (GSD) is expected and it was assumed until recently that all snakes possessed ZZ/ZW sex chromosomes. The main reason for this is that most of the studied snakes were from the group Caenophidia and in the rest of the snake lineages it was believed that their sex chromosomes were homologous. In fact, the sex chromosomes of non-caenophidian snakes have not yet been identified - with the single exception of Acrantophis dumerili. Nevertheless, a recent study showed that there was an independent evolution of XX/XY sex chromosomes in pythons and boas. Sex chromosomes of these snakes are homomorphic and so far they have not been detected by classical cytogenetic methods. In this context, the aim of this study is to explore whether it is...
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Archaeogenetics in frog's phylogenetics
Teliščaková, Martina ; Symonová, Radka (advisor) ; Majtánová, Zuzana (referee)
Key words: Archaeogenetics, palaeogenetics, molecular palaeontology, phylogeny of frog's, molecular evolution, Anura, zooarchaeology The first part of my thesis deals with archaeogenetic research issues. There are described history and important moments when the archaeogenetic mehtods were applied. It is concerned with options that archaeogenetics has and restrictions that limit its research. It also focuses on possibilities of contamination of fossil materials and aDNA degradation. You will be familiarized with its chemical properties and the second part of this work deals with molecular evolution of sequence DNA. A search follows this part. It describes archaeogenetics methods provided that they help to clarify the phylogenetics of lower vertebrates, especially the phylogeny of Frogs (Palaeobatrachus, Pipa). I pointed out the present state of knowledge of frog's archaeogentics using archaeological research findings.
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Out of Asia Minor into Danube Drainage: Phylogeography and colonisation pathways in the loach fish Cobitis strumicae
Majtánová, Zuzana ; Choleva, Lukáš (advisor) ; Reichard, Martin (referee)
The spiny loach Cobitis strumicae is a small bottom-dwelling freshwater fish whose progenitor colonised the Balkan Peninsula from the Near East through the Asia Minor. The current geographic distribution of C. strumicae forms a ring around the Stara Planina (Balkan mountains), inhabitting Danube Basin and coastal rivers of Black Sea and Aegean Sea. Using one marker of mitochondrial DNA (gene for cytochrom b) and one marker of nuclear DNA (S7 gene, first intron), we reconstructed the species distribution and phylogenetic relationship of 44 populations throughout C. strumicae distribution. We also analysed its sister species, C. punctilineata, which lives inside the distribution area of C. strumicae. Aplication of four phylogenetic approaches confirm the monophyly and species statut and endemicity of C. punctilineata, and, moreover, the evidence of secondary hybridization with C. strumicae was found. The network analysis using median-joining method showed deep divergence between the both species. Phylogenetic analyses for cyt b gene confirmed the monophyly of C. strumicae, with internal substructure into at least two well divided lineages, which suggests the process of local speciation. Phylogenetic analyses of S7 gene did not support the monophyly of C. strumicae. Instead, the two separated...
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Molecular cytogenetics of selected actinopterygian fishes: insight from repetitive sequences to whole genome analyses
Majtánová, Zuzana ; Symonová, Radka (advisor) ; Marec, František (referee) ; Šťáhlavský, František (referee)
Actinopterygian fishes exhibit the greatest taxonomical diversity of all vertebrates, making this group attractive to address numerous evolutionary questions. The role of molecular cytogenetics and cytogenomics further increase because recent advances in these fields provide more comprehensive view of fish genome organization and evolutionary dynamics, responsible for this amazing diversity. My Thesis investigates the genome organization of selected fish lineages, namely basal lineages of Actinopterygians (Lepisosteidae and Amiidae) and Teleosts (Pantodontidae), together with "modern" fishes Cobitidae and Coregonidae. I have integrated conventional and molecular cytogenetic techniques together with phylogenetic and statistical approaches. Publications included into the Thesis describe e.g. the cytogenetic variability and dynamics in closely related fish species of the genus Coregonus and the impact of repetitive sequences on the ecological speciation. In contrast to the recent cytotaxonomical diversity of Coregonids, we have detected a karyotype stability associated with asexual reproduction in spined loaches of the genus Cobitis. In the subsequent publication, we describe a surprising AT/GC genome organization in gars (Atractosteus and Lepisosteus) and summarize the knowledge of genome...
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