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Population structure, migration and dynamics in Africa and Arabia
Čížková, Martina ; Černý, Viktor (advisor) ; Frynta, Daniel (referee) ; Zrzavý, Jan (referee)
In addition to the interaction of evolutionary forces, the population history of the African Sahel and Arabia has been influenced by the spread of Neolithic cultural innovations. The reflection of these processes today is a very complex structured diversity of the current populations, which is presented here through the analysis of several genetic markers. The aim is to provide a comprehensive view of the history of demographic processes in the Sahel and Arabia, by combining genetic, linguistic, subsistence and geographical data obtained from local populations. A study of a large dataset of mtDNA sequences showed that Arabia was a major crossroads in gene flow, and although it was colonized by anatomically modern humans from East Africa, today's differentiation from Africa is greater than the differentiation between local populations in these regions. Even the Sahel was an important biocorridor in the past. Today, we encounter populations of various subsistence strategies (nomadic pastoralists and settled farmers), between which gene flow has been severely restricted. A comparison of uniparently inherited loci in both groups points to different migratory activity in the eastern and western parts of the Sahel. Analyzes of Alu elements, which indicated the inclination of West African herders (Fulbs)...
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Genetic diversity and structure of populations of Campanula glomerata on regional scale in White Carpathians
Černá, Mariana ; Münzbergová, Zuzana (advisor) ; Kotilínek, Milan (referee)
Habitat fragmentation can adversely affect species populations due to reduced genetic diversity and increased population differentiation due to habitat isolation, reduced population size, and disruption of gene flow. Many species suffer from habitat fragmentation and isolation, and Campanula glomerata is a good example of a species that is noticeably declining in many places due to changes in landscape management. The question is how the model species responds to these changes and whether is the change are reflected in genetic diversity and population structure. The aim of this work is to determine the degree of genetic diversity and to reveal the genetic structure of populations of the model species C. glomerata on a small regional scale in the White Carpathians. This system will allow us to compare populations from two different regions that have been affected to varying degrees by agricultural intensification and fragmentation in the last century. It is a southwestern and northeastern part of the region, which differs from each other in the history of management in the landscape, but also in the continuity of meadows, species composition and environmental conditions. For this purpose, I developed and optimized a total of 16 usable microsatellite markers, 4 of which come from related species of...
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Telestes perspective on the karstic poljes of eastern Herzegovina
Doulíková, Tereza ; Vukićová, Jasna (advisor) ; Choleva, Lukáš (referee)
The Dinaric karst region in the Balkans is one of the hot spots of biodiversity with a high number of endemic freshwater fish. The major cause of the high degree of endemism are numerous paleoclimatic and geological events that have affected the formation of the entire area. Flows of karst poljes represent a specific ecosystem to which some fishes have adapted. The poljes have been periodically flooded and these floods may activate different underground channels, which lead to interconnection of poljes. These fish species spend a part of the year in surface water and a part in groundwater and they may use the underground flows between poljes for migration. The aim of this thesis is to evaluate the genetic variability of two endemic fish species of the genus Telestes living in karst poljes in the region of eastern Herzegovina, and to detect a possible current gene flow between populations of these species due to the connection of underground flows. For this purpose, the DNA from 102 individuals from five different localities was isolated. The mitochondrial marker cytochrom b and 16 microsatellite loci were used for the analyses. The results point to very low variability between species and populations. Based on mitochondrial marker analysis, no link between populations of the species was detected,...
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Photobiont diversity in lichen thallus Psora decipiens
Jadrná, Iva ; Škaloud, Pavel (advisor) ; Peksa, Ondřej (referee)
Psora decipiens is a characteristic species of the terricolous lichen community Toninio-Psoretum decipientis distributed mostly on calcareous or basic substrates. The community consists in various modifications of lichens Placidium squamulosum, Toninia sedifolia, T. opuntioides, Fulgensia fulgens, F. bracteata and others. Photobionts of the lichen Psora decipiens were determined. Psora decipiens shared with Placidium sp. the single photobiont species, a common terrestrial alga Myrmecia israeliensis. Cloning of ITS rDNA revealed high intrathalline variability in M. israeliensis within a single lichen thallus. Several genotypes were often found in a thallus, uncovering either a high mutation rate of the algae or constant relichenization processes. Saxicolous Psora species (P. testacea, P. himalayana, P. valesiaca and P. rubiformis) had M. biatorellae as a photobiont, indicating a possible photobiont influence on substrate specifity of Psora lichens. Finally, the proper methodology used for identification of lichen photobionts is discussed. For a correct photobiont identification, morphological investigations of intrathaline diversity combined with coherent molecular techniques are needed. Such procedure was not applied in the former studies of Psora decipiens, resulting in a poor characterization of...
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Importance of genetic diversity of plant populations and its determinants
Sýkorová, Mariana ; Münzbergová, Zuzana (advisor) ; Dostálek, Tomáš (referee)
This thesis is mainly a review of scientific papers and professional literature dealing with genetic diversity. Nowadays, there is an extensive loss of genetic diversity that is caused by anthropogenic influences. The loss of genetic diversity is reflected in show a loss of adaptability of populations to changes in the environment, and hence the lower ability of populations to survive in their natural habitat, which can lead to the extinction of these populations and eventually to of extinction of the whole species. The aim of this bachelor thesis is to summarize the knowledge about the genetic diversity of plant species, most of them also in the context of changes in landscape management. I describe the basic indicators that determine the genetic diversity and, at the same time, factors that may affect genetic diversity, including factors influencing genetic diversity in relation to the historical state of the landscapes.
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Diversity of Blastocystis (Stramenopiles) in reptiles and arthropods
Lorencová, Markéta ; Čepička, Ivan (advisor) ; Jirků, Kateřina (referee)
The genus Blastocystis has recently attracted the attention of scientists, especially parasitologists. Similarly to the related opalines and proteromonads, Blastocystis is anaerobic and lives endobiotically in the intestine of various animals. This organism is also often found in humans, where it is associated with irritable bowel syndrome, though its pathogenic potential remains uncertain. The genus Blastocystis is remarkable for its rich genetic diversity. The taxonomy of Blastocystis is inconsistent and problematic. The strains isolated from homoiothermic vertebrates are divided into 17 subtypes, while strains from poikilotherms are either classified as separate species or are not considered in taxonomic studies at all. The aim of the study was to further examine the genetic diversity of the genus Blastocystis. We determined SSU rDNA sequences of 38 strains isolated from poikilothermic vertebrates and arthropods. The results of our phylogenetic analysis showed that Blastocystis is considerably diverse in these hosts, and we defined 21 new subtypes. The total number of known subtypes of Blastocystis has thus increased to 38. We also examined light-microscopical morphology of some strains. Most of the newly defined subtypes show identical morphology, ST20 (Blastocystis geocheloni) is an exception,...
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The genetic links around the Red Sea as revealed by the mtDNA
Čížková, Martina ; Černý, Viktor (advisor) ; Rídl, Jakub (referee)
The Red Sea region is one of the important places that allow us to uncover traces of the evolution of anatomically modern humans. Besides the questions related to its expansion out of Africa, this region is also important in terms of the mutual influence between populations of Africa and Arabia that after a long period of isolation and genetic differentiation related to climate change in the Pleistocene and subsequent development of seaways and land routes in the Holocene began to contact with each other more frequently. Number of genetic analyzes has been done but some issues concerning on the later development still remain inadequately answered, mainly because of insufficient material. This work is focused on the analysis of 200 mtDNA sequences of four Sudanese populations - two populations of nomadic herdsmen Rashaida and Beja living in the close neighborhood around the city of Kassala and speaking different languages and two populations of the Nile Valley with settled way of life. Analysis of the intrapopulation level revealed much higher diversity of the sedentary populations (in this work the sedentary populations are represented by the Nubians and Arabs). Interpopulation variability and genetic distances within other 46 populations of the Red Sea showed that although Rashaida and Beja people...
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Impact of river system structure on the genetic diversity of reed populations
Fuxová, Gabriela ; Fér, Tomáš (advisor) ; Kubátová, Barbora (referee)
Many plant species are closely related to river biotopes or to biotopes influenced by rivers. River systems create important linear corridors in ecosystems and directly or non-directly influence spatial spread of species in these environments. This offer many questions about species spread in this system. We can answer these questions by using molecular methods. Using 10 microsatellite (SSRs) primers, 202 individuals of Phragmites australis from 60 populations were analysed. Those analyses allowed reveal kinship of individuals, obtain information about spatial spread of populations and about spreading of common reed. Phragmites australis creates both - monoclonal and polyclonal - populations. Dependence of rate of clonality on environment was revealed. Populations from river banks are more monoclonal, populations from pond shores are more polyclonal. Populations are isolated. The highest percentage of variability was explained on among-population level. This is common for anemochoric species. Communication between populations is present, more on shorter distances. Evidence for vegetative spread was found on short distance. Generative spread is much more common. Long-distance spreading is mediated by generative diaspores - seeds. This spreading includes within-river spread, among-river spread and spreading...
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Diversity of the genus Blastocystis (Stramenopiles)
Lorencová, Markéta ; Čepička, Ivan (advisor) ; Kostka, Martin (referee)
Although the genus Blastocystis is only little known, it has recently attracted much attention of protistologists and parasitologists. Similarly to the related opalines and proteromonads, Blastocystis is anaerobic and lives endobiotically in intestines of many animals. On the other hand, members of the genus have completely lost flagella. Therefore, the phylogenetic position of Blastocystis had been puzzling for a long time. B. hominis is one of the most common intestinal parasites of humans and has been found also in a wide variety of animals. It is highly prevalent not only in the developing nations, but also in the developed countries. Its enormous genetic diversity, pathogenic and zoonotic potential (B. hominis is often associated with irritable bowel syndrome) make from B. hominis an important emerging pathogen.
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Dispersal, distribution and genetic diversity of Melampyrum subalpinum group
CHLUMSKÝ, Jan
This thesis is focused on the dispersal, distribution, and genetic diversity of the taxonomically highly diverse Melampyrum subalpinum group. A complete revision of the localities of M. subalpinum in the Czech Republic and Slovakia is presented. The genetic variation and population structure of the M. subalpinum group across its distribution range is described based on allozymes, nuclear and chloroplast gene sequencing, and genome size. Signs of historical hybridization with M. nemorosum were found in some populations. A comparison of seed dispersal by ants between the co-occurring M. subalpinum and M. pratense and the influence of differences in this process are presented. A new mean of seed dispersal (endozoochory) is introduced for Melampyrum. Myrmecochorous dispersal distances are tested and Holocene migration possibilities are discussed taking into account endozoochory.
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