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One Health approach to understand emerging zoonotic pathogens in the Trichophyton benhamiae complex
Čmoková, Adéla ; Hubka, Vít (advisor) ; Buchta, Vladimír (referee) ; Gené, Josepa (referee)
The Trichophyton benhamiae complex encompasses several zoonotic pathogens that are of increasing concern to the scientific community due to their epidemic spread among pets and their owners. Of particular concern is the sudden appearance and rapid spread of T. benhamiae yellow phenotype strains in Europe. Considerable genetic and phenotypic variability has been revealed in the pathogens from the complex, yet the species limits and host spectra have not been clearly elucidated. To explore the diversity, epidemiology, and taxonomy of the T. benhamiae complex, my colleagues and I formed an international, cross-disciplinary team and applied a holistic One Health approach. We collected a large dataset of strains from several continents, along with associated data about host, clinical picture, and locality. Due to the high level of clonality in commonly used DNA sequence markers, I developed a new typing schema based on ten microsatellite markers and four DNA sequence markers. We then used a polyphasic approach combining data from independent analyses to decide on species limits in the T. benhamiae complex, including phylogenetic and population-genetic analyses, phenotypic and physiological analyses, mating-type gene characterization, ecological data and MALDI- TOF mass spectrometry analysis. Thanks to...
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Populační a ochranářská genetika rysa ostrovida na okraji Západních Karpat
Stehlíková, Monika
The diploma thesis deals with the population and conservation genetics of the Eurasian lynx on the edge of the Western Carpathians, including the territory of the Beskydy Protected Landscape Area on the Czech side and the Kysuce Protected Landscape Area on the Slovak side (total ?1500 km2). The aim of the study was to evaluate using non-invasive genetic samples the temporal changes of the genetic diversity and abundance of this marginal lynx subpopulation inhabiting the Moravskoslezské Beskydy Mountains, Vsetínské Beskydy Mountains and Javorníky Mountains during the last five seasons from 2016/17 to 2020/21. Relatedness and spatial activity of selected individuals were also evaluated. The obtained genotypes were supplemented with previously genotyped individuals. In total, 37 individuals (12 females and 25 males) were detected over the period of five seasons. The estimated mean population size was 14 individuals and the effective population size varied between 3.7–7 individuals. The obtained results demonstrate the gradually decreasing genetic diversity of this subpopulation and increasing inbreeding; the inbreeding coefficient in the last season of 2020/21 recorded the highest value of FIS= 0.169. The results also showed that individuals actively reproduced there, at least 15 offspring were identified during this period, some of them settled and reproduced in the area. The spatial activity of the lynx confirmed the interconnectedness of the mountain ranges and the connection of this subpopulation to the West-Carpathian population, which is confirmed by the arrival of several unrelated individuals. In the monitored period, four individuals were also recorded to disperse westwards outside the study area, but all except of one died due to a collision with a vehicle.
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Conservation genetics of Galápagos mockingbirds: from immune genes to genomes
VLČEK, Jakub
In this thesis I have dealt with the population genetic processes of mockingbirds in the Galápagos Islands ( Mimus ) in relation to the limited island area, from the perspective of two types of immune genes and the genome-wide approach. The thesis starts with an introduction to population genetic concepts relevant to conservation genetics followed by description of immune genes: the major histocompatibility complex (MHC) and the Toll-like receptors (TLR). In the final part of the introduction, I address how genetic drift, selection and inbreeding shape genome-wide genetic patterns in small populations. The introduction is followed by four chapters, beginning with an examination of MHCII polymorphism in populations of mockingbirds in the Galápagos Islands. The study of the relationship between MHCII and the abundance of ectoparasites is the content of the second chapter. The third chapter shows how polymorphism of TLRs is shaped by interaction of genetic drift and natural selection. The last chapter deals with the effects of limited island size on inbreeding and genetic load, supported by inferences of the past demography of mockingbirds. The thesis concludes with a summary of the results and their potential implications in the field of conservation genetics.
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Reproductive strategy of the termite Silvestritermes minutus and its consequences for the life history and ecological succes
Křivánek, Jan ; Hanus, Robert (advisor) ; Klimeš, Petr (referee)
Mixed reproductive strategies are unique modes of reproduction, in which the organisms alternate sexual and asexual offspring production to benefit from both processes. In termites, such a strategy was first described in 2009 and dubbed Asexual Queen Succession (AQS). Reproduction in most termite species is based on a presence of one pair of long-lived reproductives, the primary king and queen, producing in a lifelong strict monogamy all other colony members using classical sexual processes. In a few rare species, the primary queen has been observed to be replaced at some stage of colony development by a harem of neotenic queens. These arise from unfertilized eggs via thelytokous parthenogenesis and reproduce with the founding king. While the workers, soldiers and winged dispersing reproductives remain to be produced sexually, new generations of parthenogenetic neotenic queens appear in the colony to supplement the harem. As long as the founding king is alive, the genetic constitution of most offspring remains identical as if the founding queen would still be alive, while the overall fecundity of the colony increases thanks to the large number of queens. At the same time, the continuous renewal of the harem by new parthenogens offers a virtually unlimited lifespan extension to the colony. In my...
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Genetic analysis of dicyemid infrapopulations suggests sexual reproduction and host colonization by multiple individuals is common
FLEGROVÁ, Tereza
This study explores the infrapopulation structure of Dicyema moschatum in its host Eledone moschata with the use of microsatellite markers. In order to assess the infrapopulation diversity, set of eight microsatellite markers was selected and respective oligonucleotides were designed for this population genetics study. Fragmentation method was used to analyze various microsatellite markers and the results were analyzed in bioinformatic programs that focus on standard population genetic metrics. Obtained results proved to provide new information about D. moschatum mating system and infection strategy.
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Evolution and Phylogeny of Mesozoa
DRÁBKOVÁ, Marie
This thesis focuses on the phylogenetic position of Mesozoa (Orthonectida and Dicyemida) based on phylogenomics, and on dicyemid life-history traits revealed by molecular methods used in population genetics. The thesis is introduced by the review of biology of both groups, complemented by up to now development of views on their phylogenetic position and notes concerning the study of the population structure of marine invertebrates. The introduction is followed by a study focusing on the phylogenetic position of Mesozoa, a comparison of population structure between the cephalopod host and its dicyemid parasite, and a case study of dicyemid parasite infrapopulation. The thesis wraps up with a review on cephalopod parasites and a summary.
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Population Genetics of Parasites and Their Arthropod Hosts
Bezányiová, Kateřina ; Straka, Jakub (advisor) ; Votýpka, Jan (referee)
Arthropoda are currently the largest metazoan phylum. Given that organisms with parasitic lifestyle are thought to comprise the majority of existing species, it's easy to imagine an immense diversity of parasites interacts with arthropods. However, in comparison to organisms parasitising vertebrates, parasites of arthropods are direly understudied despite their abundance, importance, and potential usefulness. Amongst other things, parasites can be used as tools allowing the inference of information on host life history, ecology, and past events the host species have experienced. Population genetic structure of parasites and other symbionts may reflect these traits and events due to their close relationship with the host. Even though parasites comprise a diverse assemblage of taxa, it's possible to identify convergent patterns in their biology. Models predicting congruent population genetic co- structuring can be thus based on a few traits such as host specificity, life cycle complexity or parasite and/or host dispersal. In some cases, the parasite may provide better resolution of population structure than the host itself, serving as a proxy that may be used to direct conservation programmes of both the host and parasite, as has already been done with parasites of vertebrates. This thesis summarises known...
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Y Chromosomal Characteristics of the Modern Rural Population in Klatovy Region
Doležalová, Veronika ; Ehler, Edvard (advisor) ; Stenzl, Vlastimil (referee)
Usage of genetic markers in non-recombining part of chromosome Y has been shown as a eligible tool for a study of history, diversity and migration of population. Applicable markers of chromosome Y are SNP and STR polymorphisms. There were collected 53 unique samples of DNA as a object of this work from unrelated origin males from 9 villages around Klatovy. Samples have been analyzed and its values have been determined by using the 17 STR markers by AmpFLSTR® Yfiler® Direct Kit. In total I have observed 7 different haplogroups. I have resulted samples from villages around Klatovy and they were analyzed by AMOVA. I have compared samples with the surrounding populations in neighborly Federal Republic of Germany, Austria, Central and South Bohemia. There were no significant differences founded in the genetic profile of this population to the surrounding populations.
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Genetická struktura mediteránních populací kaloně Rousettus aegyptiacus
Marešová, Tereza ; Hulva, Pavel (advisor) ; Bryja, Josef (referee)
5 Abstract The genus Rousettus represents the only fruit bat genus distributed both in Asia and Africa reaching northern distributional limits of the Pteropodidae family. This unusual distribution pattern is related to the ability of echolocation, subsequent cave dwelling and probably other thermoregulatory and behavioural adaptations to relatively cold and dry climate. Methods for identification of genetically discrete populations were used in the presented study to acquire better comprehension of historical ways of colonization along with current dispersal and migratory patterns of the Egyptian fruit bat (Rousettus aegyptiacus) in the Mediterranean basin and adjacent range patches. Modern approaches to population and landscape genetics were applied on a dataset comprising 553 individuals from 72 localities using 20 nuclear microsatellites. Our results revealed a significant genetic distance of East African individuals and certain substructure in the northern part of the range. Cypriot population is clearly separated, and - for higher K - the isolation of colonies from Egyptian oases is highly supported. Genetic proximity of south Arabian and Sinai populations contradict current taxonomy of the species. Our findings highlight the role of seas and deserts as barriers restricting gene flow and the evolution...
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Genetic consequences of bottlenecks and population admixture in Eurasian beaver (Castor fiber)
Náhlovský, Jan ; Munclinger, Pavel (advisor) ; Hulva, Pavel (referee)
In the last few centuries beavers passed through dramatic declining of the population size followed by expansion supported by reintroductions. The genetical variability is much decreased due to this bottleneck. Current beavers possess 31 known recent mitochondrial haplotypes, among which some were described independently several times. The haplotypes form two clusters, which serve as a base for dividing beaver populations into the west and east ESU. While microsatellite loci show moderate variability, the diversity of Y chromosome loci is very low. There are only ten described alleles of the DRB second exon, which belong to the MHC loci. No mitochondrial haplotype or MHC allele is shared between relict populations. This is not noticeable in samples from the time before the bottleneck. Described subspecies are therefore only the artefact of the recent bottleneck. Newly established populations comprise in many cases beavers of various origin and are more or less admixed. It seems, that the admixed populations have higher viability and conversely in some relict populations it is possible to find the evidence of the inbreeding depression. Thus, for reintroductions it is advantageous to use individuals from several source relict populations or to use beavers from admixed populations. Several species passed...
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