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Anticoagulation factors and blood uptake by monogeneans of the family Diplozoidae
Skipalová, Karolína ; Mikeš, Libor (advisor) ; Sojka, Dan (referee)
For the successful food intake by organisms that feed on blood is essentials presence of antihaemostatic molecules such as vasodilators, anticoagulant molecules and apyrases., Although members of family Diplozoidae (Heteronchoinea) are blood-feeding parasites on the gills of the fish, these molecules, that could disrupt host hemostasis, have not yet been identified. Thus, the aim of this study was to find molecules with potential anticoagulant activity in homogenates of whole worm bodies and excretory/secretory products of the members of family Diplozoidae. Furthermore perform bioinformatics analysis of sequences obtained from transcriptom project of Eudiplozoon nipponicum (Heteronchoinea: Diplozoidae) and selected proteins (protein domain) then expressed in a recombinant form. We tested inhibitory activity in excretory-secretory products and homogenates of members family Diplozoidae towards coagulation factors IIa and Xa and their specific fluorogenic with 4 negative and 1 positive results. From the results of two transcriptome analysis we discovered three protein families of potential anticoagulants - annexins, serpins and Kunitz-domain proteins. For further analyses we focused on the Kunitz protein family. These proteins contain one or more structurally related active domains which are able to...
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Visual cues in the coevolution of brood parasite and its hosts
Šulc, Michal ; Honza, Marcel (advisor) ; Fuchs, Roman (referee) ; Samaš, Peter (referee)
Avian brood parasitism is an ideal system for the study of coevolution. Brood parasites and their hosts have developed interesting adaptations during co-evolution allowing them to maximize their fitness. The evolution of these adaptations has a character of an "arms race" where the evolution of one trait in the host is tied with the evolution of another trait in the parasite. In my doctoral thesis, I deal with two of these adaptations: recognition of parasitic eggs by hosts and mimicry of eggs in parasites. Since both these adaptations are influenced by birds' visual system, in all my studies I used an objective method to measure the colour and the modelling of avian visual system that is quite different from the human visual system. For instance, humans in contrast to birds cannot perceive ultraviolet (UV) light. However, this part of spectrum influences behaviour of birds substantially (e.g. courtship or foraging). We found that the hosts of brood parasites can use UV light when recognizing parasitic eggs. However, it seems that this part of spectrum is not the main cue in egg recognition (manuscript 1). Ambient light has also an important impact on colour perception. We determined whether the light conditions in nests influence host responses to alien eggs. The Red Bishop (Euplectes orix) was an ideal...
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Hormonal regulation of behavioral manipulation in insects caused by parasites
Janů, Hana ; Jůzová, Kateřina (advisor) ; Žďárek, Jan (referee)
Number of scientific publications describing how parasites alter their host's behaviour providing them successful reproduction or transmission to other hosts has significantly increased during the last few decades. In recent years, more and more researchers are not only describing changes in the host organisms, but also trying to figure out mechanisms beyond these parasitic manipulations. Parasites can manipulate the host through neural and endocrine system using neuromodulators, immunomodulators, neurotransmitters and hormones. Either increase or decrease of hormone levels may cause changes of the infected hosts development, metabolism, reproduction and behaviour. Hosts, whose behaviour is altered via hormonal pathways are mostly developmentally arrested and their feeding and locomotion is terminated. Observed behavioral changes like hole digging or termination of participation in group work in insects demonstrably increase parazite's fitness. This thesis is a summary of behavioral manipulations of insects caused by changes in hormone levels.
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Variability in health state of mice in Mus musculus musculus and Mus musculus domesticus hybrid zone
Bílková, Barbora ; Vinkler, Michal (advisor) ; Vetešníková Šimková, Andrea (referee)
House mouse hybrid zone is a complex of subspecies Mus musculus musculus, Mus musculus domesticus and their hybrids. This hybrid zone is considered as a tension zone, maintained by balance between dispersion of individuals towards the zone center and negative selection against the hybrids. Decreased anti-parasite resistance could be one of selective factors which maintain the hybrid zone. In this thesis, I use hematological methods and skin-swelling test to compare variability in mouse health state within the house mouse hybrid zone. The skin-swelling test is a method measuring pro-inflammatory immune responsiveness. Since the commonly adopted method to perform this test does not allow clear interpretation of the test results, in this thesis I also aim to optimise the test protoco . I found that utilization of concanavalin A (ConA) is more suitable in mice than application of the commonly used phytohemaglutinin (PHA). Assessment of health state of mice by both hematological methods and skin-swelling test consistently indicates increased ability of anti-parasitic resistance in the subspecies M. m. musculus compared to subspecies M. m. domesticus. Hematological examination further shows better health state of hybrid individuals compared to parental subspecies. Our results support hybrid resistance hypothesis....
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Effect of parasites on haematological traits in vertebrates
Vacková, Julie ; Vinkler, Michal (advisor) ; Svobodová, Jana (referee)
Deviation out of homeostasis is reflected by physiological stress and altered immunological activity leading to changes in blood composition. Haematological examination may reveal deflection from the long-term optimum-the state of health. Haematological changes associated with parasitism are in some cases so distinctive that they allow the estimation of the parasite type affecting the host health. I aim to summarise basic methods utilised in veterinary haematology and evaluate the influence of individual groups of parasites on haematological parameters related to red and white blood cells. In vertebrates the most significant haematological changes are caused by multicellular endoparasites. Typical is eosinophilia and increased total leucocyte count. Ectoparasites are usually responsible for decrease in erythrocytes and increase in leucocytes. Extracellular bacteria increase total neutrophil and lymphocyte counts while intracellular bacteria cause decrease in all blood cell types. Viruses often decrease number of erythrocytes and leucocytes and change neutrophil/lymphocyte ratio. Changes in the haematological parameters caused by protists are difficult to generalize and not much is presently known about the influence of fungi on the blood composition in vertebrates. Variation in the effect of...
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Porcelain disease in crayfish: biology, impacts and distribution
Jelínková, Tereza ; Balcarová, Eva (advisor) ; Vávra, Jiří (referee)
The porcelain disease is a disease affecting crayfish caused by the microsporidium Thelohania contejeani. This intracellular parasite attacks muscle cells of the host and fills them with spores. This leads to white or opaque colouration of the abdominal muscle of crayfish, which is characteristic for this disease. The parasite gradually attacks more muscle fibers which probably leads to decrease of locomotor activity of affected crayfish and finally may result in their death. T. contejeani at low prevalences does not represent a real danger to crayfish populations and thus it is not as serious threat as crayfish plague. However, it has been associated with several cases of mass mortalities too. This thesis summarizes essential findings about infection by this parasite, analyzes its impacts to the host and factors that can influence transmission and progress of this disease. It also describes a life cycle of T. contejeani, summarizes records of the occurrence of this parasite and evaluates risks which it poses to crayfish populations. Finally, methods used to detect infection are described. Keywords: Thelohania contejeani, porcelain disease, crayfish, microsporidia, parasite, muscle
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Parasite's life within the host cell.
Krupičková, Alžběta ; Doležal, Pavel (advisor) ; Štáfková, Jitka (referee)
Plasmodium falciparum is one of the most dangerous human intracellular single-celled pathogen. This thesis describes the invasion, the survival and the egress of the pathogen from the host cell (erythrocyte). The main topic of the thesis is the parasite's life within the host cell in a newly created compartment, parasitophorous vacuole. By exploding hundreds of proteins Plasmodium falciparum establishes number of unique modifications inside as well as on the surface of the host cell. The thesis finishes with the chapter on the therapy and possible development of new drugs and the chapter on the parasite evolution. Powered by TCPDF (www.tcpdf.org)
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Cathepsin L by parasites - occurrence, features, functions
Perháčová, Terézia ; Mikeš, Libor (advisor) ; Kašný, Martin (referee)
Cathepsines L are lysosomal cysteine endopeptidases with an universal function in protein catabolism. This work discusses present knowledge about their characteristics in the context of their specific function in parasites. Features and function differences are described in detail on molecular level. The emphasis is on the biochemical properties with resultant use of these enzymes. Cathepsines L of kinetoplastida, aplikomplexa, entamoeba and helmints (focused on Fasciola spp and Schistosoma spp) are each discussed in appropriate chapters. Key words: hydrolase, protease, cysteine peptidase, cathepsin L, lysosome, parasite
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The metabolism of amino acids in parasitic and anaerobic protists
Jakubec, Dávid ; Šuťák, Róbert (advisor) ; Hrdý, Ivan (referee)
Parasitic protists are the cause of countless pathological conditions and economic issues in many parts of the world. While being phylogenetically unrelated, they share many similarities in their approach to satisfying the essential needs. Unlike the much studied energy metabolism, amino acids utilisation pathways are rather unexplored areas. This review shows that in many cases, the parasitic life style has not had the same impact on the amino acid metabolism as it did on the energy metabolism of the protists, which is often severely reduced. Novel pathways have been found in many of the organisms in question, for the biosynthesis of amino acids deemed both essential and non-essential in humans. The arginine dihydrolase pathway found in Trichomonas and Giardia represents a complely new way of utilising the said amino acid. The metabolism of sulfur-containing amino acid has been a matter of intensive research for their non-proteogenic roles. Polyamines are organic nitrogenous compounds involved in many vital processes in the cells, including DNA replication and protein translation. The synthesis of polyamines and their derivatives is elucidated, as it is directly connected to the amino acid metabolism. Finally, the exploitation of the unique pathways described integrates the previous research with the aim...
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Transfer of genetic information between parasite and its host
Soukal, Petr ; Hampl, Vladimír (advisor) ; Votýpka, Jan (referee)
Horizontal gene transfer (HGT) is considered a rare evolutionary event. It can take place between unrelated organisms that coexist in an intimate symbiotic relationship. Such relationship have some parasites with its host. HGT between eukaryotic parasite and its host was identified in some holoparazitic and hemiparazitic plants, the most important human protozoan parasites, microsporidias, human blood-flukes, parasitoids and fruit flies.
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