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Effect of food quality on sex ratio in a model passerine bird
Tomiška, Lubomír ; Kratochvíl, Lukáš (advisor) ; Vinkler, Michal (referee)
Sex allocation theory represents one of the key subjects of evolutionary ecology. There are several studies which bring strong evidence for relationship of environment and sex ratio in fish, reptiles, amphibians and some invertebrates. However, we still wait for answering of this question in mammals and birds. One of obstacles is the fact that in this case sex is determined by sex chromosomes. Many authors consider the chromosome segregation distortion (meiotic drive) as the most probable cause of sex ratio manipulation. But according to the traditional Mendelian conception, chromomosome segregation should be a random process. Because of new methods invented in 90's we can determine sex of an individual by molecular techniques and so find out the primary sex ratio. That's why an intensive research has occured at the turn of the century. However, there are many experimental studies we still miss reliable evidence of proximate mechanism and ultimate cause of sex ratio manipulation in birds. According to results of several studies, the sex ratio distortion occurs at primary level but nobody really tested the existence of meiotic drive directly. So we decided to test a possible cause of meiotic drive - centromere methylation. The latest research shows that methylation influences several characteristics...
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Association between human body odour and health status
Schwambergová, Dagmar ; Havlíček, Jan (advisor) ; Vinkler, Michal (referee)
The subject of this thesis is to evaluate a link between changes in body odor and health status in humans. The main aim was to create a theoretical overview of the available studies concerning humans, which are compared with studies conducted on mammals. Alteration of body odor due to the ongoing disease may negatively influence not only the odor attractiveness of a potential partner, but also may cause changes in behavioral response to a chemical stimulus for other members of the species. One may assume formation of perceptual adaptations exhibiting sensitivity to markers of health status in both sexes. Recognition of ill individuals may be crucial during social interactions, to prevent transmission of pathogens, but in mate choice the health status may also serve as an important indicator of resistance to infection, which can affect the viability of the offsprings. The main contribution of this thesis is to summarize the knowledge and insights into the area related to changes in body odor, depending on the health status. Keywords body odor, health, sexual selection, attractiveness, olfactory perception
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Adaptive evolution of Toll-like receptors in birds
Velová, Hana ; Vinkler, Michal (advisor) ; Elleder, Daniel (referee) ; Novák, Karel (referee)
Adaptive evolution of Toll-like receptors in birds Hana Velová, PhD thesis 6 Abstract Toll-like receptors (TLRs) are one of the key and presumably also evolutionary most original components of animal immune system. As Pattern recognition receptors they form the first line of innate immune defence against various pathogens. The proper receptor binding of pathogenic ligands is crucial for their correct recognition and for subsequent triggering of an appropriate immune response. Because there exists a direct interaction between the receptor surface and the pathogenic ligand, host-pathogen coevolution on molecular level can be predicted. Thus, through variability of their ligands, TLRs are exposed to extensive selective pressures that may be detected on both genetic and protein levels. Surprisingly, the variability we revealed in birds is even higher than previously expected based on the reports from other vertebrates, mainly mammals. In my doctoral thesis I summarise the results of my contribution to the avian TLR research. We were the first who experimentally verify the absence of functional TLR5 in several avian species and duplication of TLR7 in others. We finally resolved the origin of duplication in TLR1 and in TLR2 family. An important part of my research project focused on the prediction of potentially...
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Evolution of olfactory receptors
Klempt, Petr ; Stopka, Pavel (advisor) ; Vinkler, Michal (referee)
This bachelor thesis deals with the largest gene family of mammals which encode olfactory receptors. Olfactory receptors fall in rhodopsin-like GPCRs subfamily, approximately 600 - 800 millions of years old. At least from this time, olfactory receptors play, as a part of one of the oldest senses (smell), fundamental role in detection of chemical cues from water or air. This work summarizes large repertoire of olfactory receptors and its changes during the evolution of important animal taxons with emphasis on number and fraction of functional and nonfunctional olfactory receptor genes. Those values are part of criteria used for olfactory ability of animals. Olfactory receptors are typically placed on surface of sensory neuron placed in olfactory epithelium, where they bind various odorants and triggers signal cascade which leads to neuron's membrane depolarization. Therefore, about one half of this work summarizes knowledge of olfactory receptor's molecular biology like their structure, main parts of signal cascade (Gαolf, ACIII, CNG channel, Ca2+ dependent Cl- channel) just as parts needed for steady-state establishment. Expression of olfactory receptors detected in amount of non-olfactory tissues (mussels, sperm, brain etc.), indicate possibly important biomedical roles of this receptors.
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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...
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Development of selected CD markers and their role in the phylogenesis of human immune system
Podolská, Tereza ; Růžičková, Šárka (advisor) ; Vinkler, Michal (referee)
In the first part of the thesis we investigated the origin of selected surface CD markers of human, namely CD19, CD20, CD21, CD24, CD27 and CD38 molecules. In addition, nucleotide and amino acid sequences of these molecules were compared using in silico approach. Bioinformatic databases of sequences of selected molecules at DNA, mRNA and protein level, such as GeneBank, NCBI BLAST, Homologene and OrthoDB, have been used. The intent was to identify at the domain level the first organism in which it is possible to find the searched molecule. At the N-terminal domain of the CD38 of birds, a sequence showing significant similarity to the archaebacterial flagellin domain was found. This flagellin sequence in the CD38 avian molecule is located in the region of transmembrane domain, indicating that the occurrence of this sequence might be related to the formation of the transmembrane domain. The approach used here could be implemented in comparative hybridization studies as a tool in the preparatory non-laboratory phase of the research of the presence of paralogs and orthologs in phylogenetically old species. Keywords: CD marker, immunocyte, B lymphocyte, innate and adaptive immunity, sequence database, amino acid, nucleotide
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Effect of heavy metals on avian physiology
Macháčková, Eliška ; Vinkler, Michal (advisor) ; Ožana, Stanislav (referee)
Heavy metals are among the substances commonly found on earth's surface, where they have been naturally deposited from the crust over millions of years. However, with the advent of man and especially the industrial age, anthropogenic sources of these often-toxic elements increased and their concentration, especially in the human environment, increased sharply. These elements subsequently began to accumulate to a greater extent in the bodies of organisms, where they are involved in the development of various diseases, autoimmune reactions and other health problems. Bioindicators, organisms commonly found in the studied areas which are able to respond to these changes in an observable manner, are used to study such changes in the environment. Birds were selected as a suitable bioindicator for this work. The changes were observed both at the cellular level, including oxidative stress and disruption of cellular structures, as well as at the histological level. In tissues, heavy metals cause various morphological abnormalities and thus disrupt their functionality, leading to the failure of entire animal systems. As a result, there is a need to continue to focus on reducing anthropogenic pollution of the planet by these elements
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Leucocytozoon in passerines
Geržová, Lenka ; Svobodová, Milena (advisor) ; Vinkler, Michal (referee)
Leucocytozoon is the least studied genus of blood parasites of the order Haemosporida comparison with the genera Plasmodium and Haemoproteus. Its transmission is almost exclusively linked with a vector of the genus Simulium, which ensures the circulation of parasites in populations of wild and domestic birds. Numerous species have been are described by classical taxonomy, but it is assumed that this genus hides a number of cryptic species, its diversity being much higer. Methods of detection include microscopy, a classical method used for many decades, and molecular biology methods introducted at the turn of the millenium. Key words: Leucocytozoon, passerines, prevalence, species, dynamics of infection, detection
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Variability of the domestic chicken breeds in selected immunological traits of hen and egg
Bílková, Barbora ; Vinkler, Michal (advisor) ; Plachý, Jiří (referee) ; Trefil, Pavel (referee)
The avian immune system is a complex system of defence mechanisms that protect bird hosts against threats from ubiquitous pathogens. According to the co-evolutionary models, variability in immune traits of hosts is the key component providing ability to adapt and enhance their defence mechanisms in presence of constant selective pathogen pressure. Domestic chicken (Gallus gallus f. domestica) is used as a model organism in avian biology and also is one of the most important food-producing animals, not only for their meat but also for the egg production. Unfortunately, in research usually only inbred chicken lines are used and modern poultry husbandry is tight with unilateral breeding towards highly productive breeds. Those approaches decrease intra-population polymorphism in chickens. However, especially in case of farm animals, searching and extending the pool of immune variability and enhancing pathogen resistance is crucial for sustaining healthy and biologically secure populations and their products. Morphologically highly distinct traditional chicken breeds, which have evolved for hundreds years under different selective pressures, may represent this desirable immunological variability. In my thesis I described variability in chosen immunological traits, haematological parameters and proteomic...
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The effect of gut microbiota composition on condition in birds
Černá, Kateřina ; Vinkler, Michal (advisor) ; Saláková, Martina (referee)
The aim of this thesis is to summarize present knowledge concerning the effects of gut microbiota composition on condition in birds. The effect of gut microbiota on various aspects of animal physiology is currently intensively studied and the understanding of its biomedical importance is a topical theme. However, the majority of the current research is focused on humans and other mammals, and in birds on agriculturally significant species. Therefore, this thesis focuses also on the applicability of results of agriculturally orientated research on free-living birds' study. The results of agricultural research show a high interspecies and intraspecies variability in the effects of certain bacteria on the condition of the host. That should be taken into account when designing experiments in wild-living species. This thesis summarizes current knowledge concerning the effects of bacteria on condition of birds that was gained in correlational and manipulative studies. Manipulative studies include those in which probiotics or antibiotics were given to birds. The main modes of action of probiotic bacteria are also summarized here. One of the aims of this thesis was also to find out the possibilities of using detection of certain bacterial species as a non-invasive method to assess birds' condition. This thesis...
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