National Repository of Grey Literature 52 records found  beginprevious24 - 33nextend  jump to record: Search took 0.00 seconds. 
Hybrid origin of beavers in Central Europe
Albrechtová, Alena ; Munclinger, Pavel (advisor) ; Bryja, Josef (referee)
The aim of the master diploma work is to investigate origin of Czech populations and genetic variability of almost all Eurasian populations of the European beaver (Castor fiber). For our purposes we collected specimens from Czech populations, reintroduced population in Kirov district in Russia and all European and Asian refugia. At the end of the 19th century the species was on the verge of extinction due to overhunting, surviving only in eight isolated refugial areas. The population size at the end of the 19th century was estimated as 1 200 animals. The number of individuals has increased thanks to the legal protection and reintroductions. The current population size is estimated at 640 000. It is obvious that the populations of beaver have recently undergone severe bottleneck. Beaver was completely extirpated in the Czech Republic in the 18th century. Since the 80th of the 20th century beavers re-established in the Czech Republic due to migration from neighbouring countries and reintroduction programmes, however we knew only little about the origin of beavers in the Czech Republic. I showed that our beavers are derived from individuals in France, Germany, Norway and east Europe. Mitochondrial DNA of Castor canadensis has not been found in Czech beavers. I studied microsatellite loci (first use for...
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...
Regulatory mechanisms of WNT signalling
Pospíchalová, Vendula ; Kořínek, Vladimír (advisor) ; Trka, Jan (referee) ; Bryja, Josef (referee)
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Phylogeny and biogeography of Neotropical and African riverine cichlids: multilocus phylogenetic methods in the evolutionary studies
Musilová, Zuzana ; Novák, Jindřich (advisor) ; Bryja, Josef (referee) ; Reichard, Martin (referee)
Summary: The thesis comprises from the introduction and five main parts: three of them are published papers, the rest two are manuscripts prepared for submitting to the scientific journals. The first two are published phylogenetic studies of the cichlasomatine cichlids based on (1) molecular characters, and (2) both morphological and molecular data with the description of a new genus Andinoacara. The third (3) is the already published description of the new species Andinoacara stalsbergi from Peru combining both morphological and phylogenetic approaches and including the detailed phylogeny of the genus Andinoacara. The next unpublished manuscript (4) is the more detailed comprehensive phylogeography of the two non-relative genera (including Andinoacaras) of the trans-Andean cichlids. Including all valid species from the majority of their distribution areas it was reconstructed the ancestral area of both genera in the Choco region, Colombia, and revealed the directions of their distribution spreading. The last (5) unpublished manuscript is the phylogeographical study of the cichlid genus Serranochromis from the headwaters of the totally unknown Central Angola. It showed several evidences of the faunal exchange among the adjacent river systems. Lastly, the thesis is supplemented by several appendices...
Alternative reproductive strategies in Common Pochards (Aythya ferina)
Šťovíček, Ondřej ; Albrecht, Tomáš (advisor) ; Bryja, Josef (referee)
Conspecific brood parasitism (CBP) is one of few alternative reproductive strategies exmployed by females. CBP is common in birds because of their mode of reproduction (ovipary), which allows relatively simple dumping own eggs to foreign nest. This strategy is especially common in birds with precocial young, such as waterfowl. In this study, common pochard (Aythya ferina) was the model organism for study of CBP via molecular methods. It is the very first evidence of this kind of parasitism in non-colonial and non-cavity nesting duck species, based on detection of parasitic eggs via microsatellites markers. A set of 17 microsatellites markers (10 of these were newly found and specific for our species) was optimised for detection of rate of parasitism and relatedness between females in whole population. It was found that CBP is surprisingly high in our species, the parasitic eggs (39 % of 252 eggs) were found in 89% of nests. Despite the fact that females preferentially nest near relatives individuals, parasitic females parasitize equally nests nearby and nests in longer distance. However, no preferential parasitism of related individuals was found. Cost of parasitism seems relatively low for both, host and parasite, in our species. This is in accordance with previous finding that common pochard's...
Recently active L1 and B1 retrotransposons in the mouse genome
Janoušek, Václav ; Munclinger, Pavel (advisor) ; Bryja, Josef (referee)
The work focuses on two recently active retrotransposon families in the house mouse genome. They are L1 and B1 retrotransposons. The aim of the work was to find polymorphic retrotransposon insertions caused by their recent activity. Two genomes of mouse inbred strains derived from the different house mouse subspecies were compared. The BACends from MSM/Ms derived from M. m. molossinus were compared with the reference genome of C57BL/6J derived mostly from M. m. domesticus. The set of output insertions was classified into several subfamilies of B1 a L1 families. The presence/absence of these insertions was tested using PCR in all three house mouse subspecies and also in two sister species (M. spretus and M. macedonicus). The particular subfamilies differed with regard to presence in latter species. Despite the supposed lack of activity of older L1 families (F2 and F3) they persist in house mouse population as an ancestral polymorphism. Unlike L1 subfamilies, B1 subfamilies appear to be active in house mouse genome for longer period of time. Also the difference between the whole families L1 and B1was observed. Thus, according to my data L1 family seems to be recently more active than B1 family.
Gentic structure of isolated populations of the Scarlet rosefinch (Caprodacus erythrinus)
Šašková, Lucie ; Munclinger, Pavel (advisor) ; Bryja, Josef (referee)
Diplomová práce se zabývá původem a demografickými charakteristikami geograficky izolovaných, nedávno vzniklých populací hýla rudého (Carpodacus erythrinus) na západním okraji areálu druhu. Práce je zalo.ena na nově získaných sekvencích dvou úseků mitochondriální DNA (410 páru bazí dlouhá sekvence kontrolní oblasti a 1029 dlouhá sekvence genu ND2) zji.těných u 82 jedinců ze 13 lokalit a jejich srovnáním s publikovanými sekvencemi z kontinuálního areálu. Zjistila jsem, .e geograficky izolované populace ze střední a severní Evropy nejsou významně geneticky izolované od populací kontinuálního areálu. Nově vzniklé populace také vykazují překvapivě vysokou diverzitu srovnatelnou s asijskými populacemi. Tato zji.tění nasvědčují intenzivnímu toku genů mezi populacemi zprostředkovanému pravděpodobně převá.ně disperzí mladých ptáků před prvním zahnízděním. Navzdory intenzivnímu toku genů mezi kontinuálním areálem a středo- a severoevropskými izolovanými populacemi hýli z Kavkazu, Bulharska a Turecka utvořili jasně oddělenou skupinu, která byla podpořena na základě několika typů analýz. Zdá se tedy, .e jedinci z těchto oblastí mohou mít vlastní oddělené zimovi.tě, komunikují jen minimálně se zbytkem areálu a díky tomu jsme zde zřejmě svědky počínající speciace. Klíčová slova: Hýl rudý (Carpodacus...
Genetic structure of Central European populations of hedgehogs Erinaceus europaeus and E. roumanicus
Bolfíková, Barbora ; Hulva, Pavel (advisor) ; Bryja, Josef (referee)
In the Czech Republic there is a wide zone of sympatric occurrence of two hedgehog species - Erinaceus europaeus and E. roumanicus, which is of Holocene origin. This work is based on genetic data obtained in 248 specimens, the sampling was focused on the area of Central Europe. We have used 410 bp long partial sequence of mtDNA control region and 9 microsatellite loci. With aid of different methods, we attempted to reveal details of distributions, population structure, demographic history and potential gene flow between both species. We have detected significantly higher occurrence of E. europaeus (3 times) compared to E. roumanicus and the shift of range borders in scale of tens of kilometers in last 30 years. Genetic variability was higher in E. europaeus. In E. roumanicus, there was support for moderate population increase, while the population size in E. europaeus seems to be stable. We have detected deviations from Hardy-Weinberg equilibrium in some loci, which could be ascribed to the Wahlund effect. We did not detect existence of hybridization or introgression, the complete precopulatory reproductive barriers have been formed supposedly. Powered by TCPDF (www.tcpdf.org)

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