|
|
MHC class I allelic variability and pro-inflammatory responsiveness in domestic fowl breeds
Pojezdná, Anežka ; Vinkler, Michal (advisor) ; Hyršl, Pavel (referee)
Domestic fowl (Gallus gallus f. domestica) is an economically important model species in science. Knowledge of the immune system of this species is therefore crucial. In research the commercial stocks are usually used together with laboratory inbred lines. They have an unnatural variability, as a result of inbreeding, their genetic and phenotypic variability is reduced. This laboratory lines are therefore not the best model for research of variability. Presently, genetically diversified poultry populations can be found in rural stocks and fancy breeds. These breeds could be good model for research in variability of immunoresponse. In this thesis, I try to map the genetic variability of the binding site of MHC class I glycoproteins in fowl breeds. In chickens are these molecules encoded in duplicated gene called BF (BF1 and BF2). These genes are relatively well known and considerable variability has been described in domestic fowl. Our results suggest a high genetic variability of MHC I in domestic fowl breeds. We had identified 41 haplotypes in 25 individuals of 14 breeds, including 7 haplotypes already known from the literature. I also focused on proinflammatory activity in fowl breeds. I watched swelling of tissue and expression of pro-inflammatory cytokines IL-6 and IL-1 after subcutaneous...
|
|
|
The role of triploid hybrids in mixed-ploidy populations of Tripleurospermum inodorum (Asteraceae)
Jirsáková, Hana ; Čertner, Martin (advisor) ; Kolář, Filip (referee)
The doubling of the nuclear genome is considered to be one of the main ways in which new sympatry plant species can arise. Polyploidy is also generally a significant source of new evolutionarily advantageous abilities. However, it is not always that way, polyploids with an odd number of chromosome sets have often limited viability and fertility. In cytotype mixed populations of diploids and tetraploids, or in diploid populations alone with the contribution of high rate of unreduced gametes formation may produce triploid hybrids. In some cases, their vitality is even comparable with parental cytotypes but they produce only a small number of offsprings and in addition of different ploidy levels. Although it has been recently thought that they have no evolutionary significance, now based on many experimental works it is known with confidence that they can significantly participate in the new polyploid formation. If triploids occur in the population with sufficient frequency, they may play a role in stabilizing of the common coexistence of diploid and tetraploid cytotypes. Triploid hybrids may despite their limited fertility contribute to the bi-directional gene flow between their parents, and thus overcome the barrier of their different ploidy levels. A suitable model to study the role which can the triploid...
|
|
|
Dynamics of rare and threatened species on local and regional scale- from theory to practice
Lampei Bucharová, Anna ; Münzbergová, Zuzana (advisor) ; Tichý, Lubomír (referee) ; Jiménez, Ares (referee)
To assess the status of a rare plant species, we must first understand the factors that affect the size of populations and their numbers. In this thesis, I study processes affecting plant species prosperity on local scale (paper 1), factors influencing species distribution in landscape and ability of species to colonize new habitats (paper 2) and species traits responsible for gene flow between established populations (paper 3). Since I work with rare plants, I also aim to turn theoretical knowledge into practical recommendations for nature conservation (paper 4) to help effectively preserve rare and endangered species. In the first 3 papers, I work with two rare fern species restricted to serpentine rocks, Asplenium adulterinum and A. cuneifolium, in a study system covering 10 × 10 km. I found that both species are long living (several decades) and in the study region, populations are in a good state and slowly growing. Even very small populations (10 individuals) have quite high chance to survive. In both fern species, I found dispersal limitation, which might be surprising regarding huge production of small spores in ferns (paper 2). The species differ in ploidy and thus, also mating system. A. adulterinum is tetraploid and its main breeding system is intragametophytic selfing. A. cuneifolium is...
|
|
|
Interspecific hybridization in Acrocephalus warblers.
Majerová, Veronika ; Reifová, Radka (advisor) ; Kotlík, Petr (referee)
Acrocephalus warblers have gone through the adaptive radiation during last severalmillion years, which gave rise to thirty one species occupying mainly Eurasia,Africa and Australia. The majority of species are morphologically very similar,however, they differ in ecological requirements, migration strategy, and song.Interspecific hybridization seems to be quite common among Acrocephaluswarblers, not only between sister species, but also between more distantly relatedtaxa. The main goal of this study was to determine whether this hybridization leadsto gene flow between species and which factors affect the rate of interspecific geneflow. For this purpose we conducted population-genetic analysis in three Europeanspecies of the Acrocephalus warblers of the subgenus Notiocichla: reed warbler (A.scirpaceus), marsh warbler (A. palustris), and blyth's reed warbler (A. dumetorum).Our results based on the analysis of sequence data from eight nuclear loci indicate,that gene flow between the studied species occurs, but only in one direction. Thegene flow is higher between genetically more related species than betweenecologically more similar species. We also estimated that the reed warbler and themarsh warbler diverged approximately 1,1 million years ago. The blyth's warblerand ancestor of the reed and marsh warbler...
|
|
| |
guest ::
