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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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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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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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Dispersion of freshwater gastropods
Buďová, Jana ; Černý, Martin (advisor) ; Juřičková, Lucie (referee)
Freshwater gastropods (Mollusca: Gastropoda) belong to two tradional taxonomic groups: prosobranchs (Prosobranchia) and pulmonates (Pulmonata). Most of these molluscs are characterized by low vagility. Therefore they usually rely on passive dispersal. Their dispersal vectors are mostly birds and water. Animals can transport snails both externally and internally. Direct methods (capture.mark.recapture, radio - tracking) and genetic methods could be used to study dispersal. For genetic studies can be used many type of molecular markers, but the recently most popular are microsatellites. According to recent studies, the dispersal of freshwater gastropods is probably not as frequent and wide - spread as assumed before. Key words: freshwater snails, dispersal, dispersal vectors, capture - mark - recapture, molecular markers, population genetics
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Population Structure of African Populations Inferred from Alu Insertions.
Fajkošová, Zuzana ; Černý, Viktor (advisor) ; Frynta, Daniel (referee)
The population genetic study was carried out on 188 unrelated individuals from 5 populations of the Sahel. Relationships of nomadic Fulani to sedentary populations of different linguistic backgrounds and geographic origins were inferred from 16 polymorphic Alu insertions. Bayesian clustering approaches could be applied due to biallelic multilocus nature of the data. Fulani were shown to be divergent from neighbouring sedentary populations (Kassena and Mossi) and similar to Somali of East Africa. In context of already published genetic data, these results could be interpreted as Saharan origin of Fulani diaspora that was caused by Sahara drying out around 6 000 BP. After this initial migration of nomads to West Africa, a primarily female gene flow (integration of females) must have influenced the Fulani population. In contrast to Fulani, Songhai have shown a signal of recent admixture in concordance with historical and linguistic assumptions. KEY WORDS Alu insertions, Fulani, population genetics, Sahel
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