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Společenstva vodních makrobezobratlých ovlivněna lidskými činnostmi
LET, Marek
2022 - anglický
Bezobratlí představují významnou součást vodních ekosystémů, podílející se na řadě nezbytných ekosystémových služeb. Narušením stanovišť a druhově i funkčně rozmanitých společenstev může snadno dojít k jen těžko vratným změnám. Tato práce byla zaměřena na výzkum vztahů společenstev vodních bezobratlých ovlivněných lidskou činností. Byl pozorován obecně negativní vztah mezi gradientem kontaminace insekticidy a četností proudomilných bezobratlých na úrovni vyšších taxonomických jednotek (Kapitola 2). Gradient hydrologického sucha negativně koreloval s četností skupiny jepic (Ephemeroptera), pošvatek (Plecoptera) a chrostíků (Trichoptera) - dále jen EPT - a nejlépe pozitivně koreloval s četností dospělců brouků (Coleoptera), ploštic (Heteroptera), lasturnatek (Ostracoda) a berušek vodních (Asellus aquaticus). Na základě porovnání stavu společenstva v kontrolním odběrového úseku se stavy společenstev z úseků zasažených počáteční insekticidní otravou byl předpokládán nepříznivý synergický efekt hydrologického sucha a splachů ze zemědělsky obhospodařovaných ploch. Metody v moderním zemědělství lze považovat za jednu z největších hrozeb pro vodní bezobratlé. Výsledky shrnuté v Kapitole 3 ukazují klesající zaznamenaný počet druhů EPT (avšak nikoliv četnosti EPT jedinců) spolu s rostoucí kumulací antropogenních faktorů. Nicméně pouze společenstva jepic a obzvláště pošvatek vykazovala signifikantní úbytky, zatímco chrostíci vykazovali určitou rezistenci k předpokládaným nejsilnějším antropogenním faktorům. Tyto hlavní faktory zahrnovaly zatížení kovy (kadmium, olovo a zinek) s následným vyústěním městských vyčištěných a špatně vyčištěných odpadních vod s obsahem pesticidů, léčiv, organického materiálu ze splašků a nepochybně i řady dalších neanalyzovaných látek. Navzdory zvýšené četnosti chrostíků byly u čeledí Hydropsychidae, Limnephilidae a Rhyacophilidae pozorovány známky zhoršené kondice (malformace a přítomnost uhynulých kukel) v obou typech znečištění. Prostředí znečištěné odpadními vodami bylo osídleno signifikantně zvýšeným podílem pasivních filtrátorů a predátorů z řádu chrostíků. Vidím zde nutnost dále studovat reakce společenstev vodních organismů na přísun vyčištěných odpadních vod, jelikož technologie čištění jsou v mnoha zemích světa stále zdokonalovány a je k dispozici poměrně málo publikovaných výstupů sledujících efekty zaváděných postupů na přirozené vodní ekosystémy. Kapitola 4 odhaluje negativní působení nepůvodního raka signálního (Pacifastacus leniusculus) na původní komunitu potočnic (Branchiobdellidae). Dle našich výsledků může úplné nahrazení původního raka říčního (Astacus astacus) rakem signálním vést k vymizení sledovaných dvou druhů potočnic, Branchiobdella parasita a B. pentadonta. Na lokalitě se sympatrickým výskytem raka říčního a signálního byly rovněž pozorovány potenciální rozdíly mezi oběma raky v korelacích mezi četnostmi obou druhů potočnic. Četnosti větší potočnice B. parasita pozitivně korelovaly s četností menší B. pentadonta pouze u raka signálního, přičemž tento vztah může být až negativní u velkých hustě osídlených jedinců raka říčního. Byla tudíž předpokládána potenciální kompetice o životní prostor. Doprovodný laboratorní experiment ukázal, že rak signální se mechanicky zbavuje epibiontů ve vyšší míře ve srovnání s rakem říčním. Výsledky tedy demonstrují potenciální ztráty v biodiverzitě nenápadných skupin organismů vznikající introdukcí invazních druhů. Poznatky v oblasti reakcí přírodních společenstev vodních bezobratlých na člověkem vyvolané změny v životním prostředí mohou být důležité například při posuzování důsledků nově plánovaných nebo aktuálně působících antropogenních činností v kulturní krajině. Tato dizertační práce rovněž poskytuje zpětnou vazbu laboratorním studiím, jejichž aplikovatelnost na reálné podmínky je často omezena zjednodušeným umělým prostředím. Macroinvertebrates represent an essential part of aquatic environments contributing to various ecosystem services. Disregarding the importance of their habitats and stable and functionally diverse communities can cause hardly reversible losses. This Thesis aimed to reveal relationships between responses of aquatic macroinvertebrate communities and the consequences of human activities. The general negative relationship between the gradient of insecticide contamination and abundances of higher taxonomic units of the stream macroinvertebrates was observed (Chapter 2). The gradient of droughts correlated negatively to the abundances of mayflies (Ephemeroptera), stoneflies (Plecoptera) and caddisflies (Trichoptera) - hereinafter referred as "EPT" - and the most positively to the abundances of coleopteran adults, heteropterans, ostracods, and water lice. Disturbing synergic effects of droughts and agricultural runoff were assumed based on the comparisons between communities sampled in the control site and initially contaminated downstream sites. The practices in modern agricultural systems can be considered one of the greatest threats to aquatic macroinvertebrate fauna. Results summarised in Chapter 3 show decreasing richness of EPT taxa (however, not their abundances) along with the involvement of an increasing number of anthropogenic factors. Nevertheless, only the mayflies and especially stoneflies showed significant negative responses, whilst caddisflies generally exhibited resistance to the presumably strongest anthropogenic factors; namely to contamination by trace metals (cadmium, lead and zinc) and to subsequent loads of treated and "poorly treated" municipal wastewaters containing pesticides, pharmaceutical active compounds, sewage-derived organic matter, and undoubtedly other not identified kinds of pollutants. Despite the higher caddisfly abundance, there were detected signs of worsened health status in hydropsychids, limnephilids and rhyacophilids, particularly detected malformations and the presence of dead pupae in both types of contaminated environments. However, the environment polluted by wastewaters exhibited a significant relationship to a highly increased relative contribution of passive filter feeders and predators within the EPT community. Since wastewater treatment technologies have been enhanced in many countries and there is a lack of published evidence about their complex effect on aquatic ecosystems, future studies are required. Chapter 4 reveals the negative effect of non-native signal crayfish (Pacifastacus leniusculus) on the native branchiodellid community. According to our results, the total replacement of the native noble crayfish (Astacus astacus) by signal crayfish can lead to the disappearance of two species Branchiobdella parasita and B. pentadonta. Potential differences between crayfish species in correlations between abundances of both branchiobdellids were observed in the locality with the sympatric occurrence of noble crayfish and signal crayfish; the abundance of bigger-sized B. parasita positively correlated to the abundance of B. pentadonta only in the signal crayfish, whilst this relationship may be negative in the big-sized noble crayfish densely infested by both species. Potential competition for space was assumed. The experiment in laboratory conditions revealed more intensive grooming in signal crayfish. The results demonstrate the loss of overlooked biodiversity associated with the invasive species introduction. Knowledge of how communities of aquatic invertebrates respond to anthropogenic changes in the environment can be useful, e.g., during the assessment of the implications of planned or currently active human interferences for cultural landscapes. This Thesis will provide useful information for laboratory studies, of which the interpretation is often limited as they are carried out in artificial environments.
Klíčová slova:
Makrozoobentos; Environmentální podmínky; Disturbance; Znečištění; Degradace stanovišť
Plné texty jsou dostupné v digitálním repozitáři JČU.
Společenstva vodních makrobezobratlých ovlivněna lidskými činnostmi
Bezobratlí představují významnou součást vodních ekosystémů, podílející se na řadě nezbytných ekosystémových služeb. Narušením stanovišť a druhově i funkčně rozmanitých společenstev může snadno dojít ...
Reproductive diapause in males of the linden bug, Pyrrhocoris apterus
HEJNÍKOVÁ, Markéta
2022 - anglický
This thesis focuses on the male reproductive diapause in the linden bug, Pyrrhocoris apterus. We examined in detail the response of males to changing photoperiodic conditions, the change in levels of juvenile hormone, and its role in male diapause, as well as the effect of low temperature on diapause termination. We compared the physiology of males and females and pointed out important sexual dimorphism in the control of diapause. Finally, we analyzed a completely novel insect neuropeptide to and explored its possible link in the chain of control of reproductive diapause. This thesis focuses on the male reproductive diapause in the linden bug, Pyrrhocoris apterus. We examined in detail the response of males to changing photoperiodic conditions, the change in levels of juvenile hormone, and its role in male diapause, as well as the effect of low temperature on diapause termination. We compared the physiology of males and females and pointed out important sexual dimorphism in the control of diapause. Finally, we analyzed a completely novel insect neuropeptide to and explored its possible link in the chain of control of reproductive diapause.
Klíčová slova:
Reproductive diapause; juvenile hormone; males; Methoprene-tolerant; Taiman; Corpus allatum; accessory glands; fertility
Plné texty jsou dostupné v digitálním repozitáři JČU.
Reproductive diapause in males of the linden bug, Pyrrhocoris apterus
This thesis focuses on the male reproductive diapause in the linden bug, Pyrrhocoris apterus. We examined in detail the response of males to changing photoperiodic conditions, the change in levels of ...
Biodiversity of Myxozoa based on extensive screening of fish and environmental samples
LISNEROVÁ, Martina
2022 - anglický
Myxozoans represent a group of morphologically simplified endoparasites infecting mainly fish, annelid and bryozoan hosts including more than 2,600 nominal species. However, the diversity seems to be unexplored and undervalued. Host searching and invasive dissection is a commonly used method for the identification of myxozoan species diversity. Metabarcoding and amplicon analyses of environmental DNA from sediment, water and soil is developing approach for biodiversity assessment and have been performed in many biological areas to identify the diversity of organisms, communities and populations. Using classical morphological and molecular approaches, we explored the myxozoan diversity in selected areas and host groups. In addition, we propose a new methodological approach for the studying of myxozoan diversity based on environmental DNA from sediment and amplicon sequencing. Illumina Mi-Seq with metabarcoding and newly designed primer sets is suitable for analyzing myxozoan communities without the need to find and capture intermediate or final hosts.
Klíčová slova:
Myxozoa; Diversity; Phylogeny; eDNA; elasmobranchs
Plné texty jsou dostupné v digitálním repozitáři JČU.
Biodiversity of Myxozoa based on extensive screening of fish and environmental samples
Myxozoans represent a group of morphologically simplified endoparasites infecting mainly fish, annelid and bryozoan hosts including more than 2,600 nominal species. However, the diversity seems to be ...
Assembly and analysis of repeat-rich regions of plant genomes
VONDRAK, Tihana
2022 - anglický
Satellite DNA has been identified in varying proportions in many eukaryotic genomes. It consists of monomeric units arranged in tandem into long, homogeneous arrays. Due to its repetitive nature, satellite DNA is difficult to assemble and analyze, and has therefore been largely neglected in research. With the development of next generation sequencing technologies such as Illumina, research on satellite DNA has intensified and our understanding of it has improved. However, the information we obtain with Illumina reads is limited by their short length. While we can characterize the sequence of satellite DNA and its abundance in genomes, it is not possible to study the long-range organization of satellite DNA, which limits our understanding of the origin and evolution of satellite DNA. This limitation can be addressed by using the latest generation of sequencing technologies that generate much longer reads of tens to hundreds of kilobases. The goal of this work was to develop bioinformatics approaches for analyzing the properties of satellite DNA arrays from long sequence reads or from genome assemblies generated with these reads. These were then used to analyze populations of satellite repeats throughout the genome or in the specific type of chromatin in three plant species that differ in the organization of their centromeres.
Plné texty jsou dostupné v digitálním repozitáři JČU.
Assembly and analysis of repeat-rich regions of plant genomes
Satellite DNA has been identified in varying proportions in many eukaryotic genomes. It consists of monomeric units arranged in tandem into long, homogeneous arrays. Due to its repetitive nature, ...
Interaction of tick-borne encephalitis virus with host and vector cells
TYKALOVÁ, Hana
2022 - anglický
The proposed thesis deals with the various aspects of tick-borne encephalitis virus infection in the host and the vector on the cellular level. It uncovers transcriptomic and proteomic responses in infected cells in the human neurons and astrocytes, and vector cells. It identifies the subgenomic flaviviral RNA as an important pathogenesis effector that can interfere with the vector RNAi pathway, and at the same time denotes the components of this pathway. It also describes the phenomenon of impairment of host protein and rRNA synthesis upon TBEV infection. Moreover, it uncovers the importance of quasispecies in the adaptation to vector and host cells. The proposed thesis deals with the various aspects of tick-borne encephalitis virus infection in the host and the vector on the cellular level. It uncovers transcriptomic and proteomic responses in infected cells in the human neurons and astrocytes, and vector cells. It identifies the subgenomic flaviviral RNA as an important pathogenesis effector that can interfere with the vector RNAi pathway, and at the same time denotes the components of this pathway. It also describes the phenomenon of impairment of host protein and rRNA synthesis upon TBEV infection. Moreover, it uncovers the importance of quasispecies in the adaptation to vector and host cells.
Klíčová slova:
tick-borne encephalitis virus; tick cells; neural cells; immune response; RNAi pathway; translational shut-off; transcriptional shut-off; quasispecies; transcriptomic; proteomics
Plné texty jsou dostupné v digitálním repozitáři JČU.
Interaction of tick-borne encephalitis virus with host and vector cells
The proposed thesis deals with the various aspects of tick-borne encephalitis virus infection in the host and the vector on the cellular level. It uncovers transcriptomic and proteomic responses in ...
Interactions between plants, herbivorous insect and predators: mechanisms and ecological importance
MRÁZOVÁ, Anna
2022 - anglický
Práce popisuje interakce mezi třemi trofickými úrovněmi z různých pohledů. Zaměřuje se na roli rostlin, býložravého hmyzu a bezobratlých predátorů a ptáků v trofických interakcích. Konkrétně popisuje nepřímo vyvolanou obranu rostlin a komunikaci rostlin s vyššími taxony a změny v predačním tlaku a společenstvech hmyzu vyvolané obrannými chemickými látkami uvolňovaných z rostlin poškozených herbivory. The thesis describes the interactions between the three trophic levels from different perspectives. It focuses on the role of plants, herbivorous insect, and invertebrate predators and birds in trophic interactions. More specifically, it describes indirectly induced plant defence and communication with higher taxa and changes in predation pressure and insect communities in response to defensive chemical compounds released from herbivory-damaged plants.
Klíčová slova:
Tritrofické interakce; obrana rostlin; býložravý hmyz; predace; ptáci; methyl jasmonát
Plné texty jsou dostupné v digitálním repozitáři JČU.
Interactions between plants, herbivorous insect and predators: mechanisms and ecological importance
Práce popisuje interakce mezi třemi trofickými úrovněmi z různých pohledů. Zaměřuje se na roli rostlin, býložravého hmyzu a bezobratlých predátorů a ptáků v trofických interakcích. Konkrétně popisuje ...
Beneficial and toxic effects of REE in algae and plants
ASHRAF, Nermeen
2022 - anglický
Lanthanides mainly represented by REE are the most frequently occurring elements as compared to arsenic and lead. REE consist of a group of elements associated with each other in terms of common physical and chemical properties, with studies concerning phytoremediation and physiological effects of such elements on living biota, is important to be addressed as these elements are frequently being considered as emerging pollutants because of excessive mining and release into the environment. Very important is to study the toxic effects of lanthanum in microalgae under environmental conditions. Experimental trials are evaluating especially potential risks on growth and photosynthesis under nanomolar-dose, with promising decrease and acute toxicity. To this end, the two most promising La-binding protein is currently investigated in green microalgae (Desmodesmus quadricauda) with high affinities. Subcellular localization patterns of La have been also shown to predict possible expression sites and to understand the metabolic response of La in microalgae. We also identify accumulator plant species for LREE in contaminated mining areas for phytoremediation purposes, aim of this study was conducted in the Brazilian mining area for REE and as well as identifying the bioavailable content which can help in predicting the promising species. This field study was done for finding new accumulators which are involved in concentrating LREE in above-ground parts. Our study suggests toxic effects of La and identified preferentially good hyperaccumulator plant specie Christella dentata for phytomining of lanthanides. This could be used as a predictive bioaccumulator in phytoremediation and its further analysis can be a part of future studies for insight mechanisms using analytical techniques, involving the identification of La-binding proteins in Desmodesmus quadricauda. Lanthanides mainly represented by REE are the most frequently occurring elements as compared to arsenic and lead. REE consist of a group of elements associated with each other in terms of common physical and chemical properties, with studies concerning phytoremediation and physiological effects of such elements on living biota, is important to be addressed as these elements are frequently being considered as emerging pollutants because of excessive mining and release into the environment. Very important is to study the toxic effects of lanthanum in microalgae under environmental conditions. Experimental trials are evaluating especially potential risks on growth and photosynthesis under nanomolar-dose, with promising decrease and acute toxicity. To this end, the two most promising La-binding protein is currently investigated in green microalgae (Desmodesmus quadricauda) with high affinities. Subcellular localization patterns of La have been also shown to predict possible expression sites and to understand the metabolic response of La in microalgae. We also identify accumulator plant species for LREE in contaminated mining areas for phytoremediation purposes, aim of this study was conducted in the Brazilian mining area for REE and as well as identifying the bioavailable content which can help in predicting the promising species. This field study was done for finding new accumulators which are involved in concentrating LREE in above-ground parts. Our study suggests toxic effects of La and identified preferentially good hyperaccumulator plant specie Christella dentata for phytomining of lanthanides. This could be used as a predictive bioaccumulator in phytoremediation and its further analysis can be a part of future studies for insight mechanisms using analytical techniques, involving the identification of La-binding proteins in Desmodesmus quadricauda.
Klíčová slova:
lanthanides; microalgae; growth; photosynthesis; La-binding protein; subcellular localization; phytoremediation; LREE; hyperaccumulator; Christella dentata
Plné texty jsou dostupné v digitálním repozitáři JČU.
Beneficial and toxic effects of REE in algae and plants
Lanthanides mainly represented by REE are the most frequently occurring elements as compared to arsenic and lead. REE consist of a group of elements associated with each other in terms of common ...
Evolution and Phylogeny of Mesozoa
DRÁBKOVÁ, Marie
2022 - anglický
This thesis focuses on the phylogenetic position of Mesozoa (Orthonectida and Dicyemida) based on phylogenomics, and on dicyemid life-history traits revealed by molecular methods used in population genetics. The thesis is introduced by the review of biology of both groups, complemented by up to now development of views on their phylogenetic position and notes concerning the study of the population structure of marine invertebrates. The introduction is followed by a study focusing on the phylogenetic position of Mesozoa, a comparison of population structure between the cephalopod host and its dicyemid parasite, and a case study of dicyemid parasite infrapopulation. The thesis wraps up with a review on cephalopod parasites and a summary.
Klíčová slova:
Mesozoa; Dicyemida; Orthonectida; Phylogenomics; Population genetics; Marine biology; Parasites
Plné texty jsou dostupné v digitálním repozitáři JČU.
Evolution and Phylogeny of Mesozoa
This thesis focuses on the phylogenetic position of Mesozoa (Orthonectida and Dicyemida) based on phylogenomics, and on dicyemid life-history traits revealed by molecular methods used in population ...
Effect of distinct soil horizon and vegetation on soil microbiome abundance, composition, and activity of Arctic permafrost
VARSADIYA, Milankumar
2022 - anglický
In the present work, I studied the abundance, composition, and activity of soil microbial communities involved in the decomposition of soil organic matter (OM) in different horizons and under distinct tundra vegetation of Arctic permafrost soils. Special emphasis was given to buried topsoil caused by cryoturbation processes. The enzyme activity and their stoichiometry were also analyzed to determine the limitation of microbial carbon, nitrogen, and phosphorus. I also applied the metatranscriptomics approach to study the active microbial community in a complex view of all three domains of life (bacteria, archaea, Eukaryota). With this approach, we could better understand the potential role of microbial interactions (e.g., bacterial predation) in the carbon and nitrogen cycles of permafrost soils.
Klíčová slova:
Microbes; Soil organic matter; Climate change; Arctic Permafrost; Tundra Vegetation
Plné texty jsou dostupné v digitálním repozitáři JČU.
Effect of distinct soil horizon and vegetation on soil microbiome abundance, composition, and activity of Arctic permafrost
In the present work, I studied the abundance, composition, and activity of soil microbial communities involved in the decomposition of soil organic matter (OM) in different horizons and under distinct ...
Study of Cancer Immunotherapy Mechanisms in Pancreatic Adenocarcinoma and Pheochromocytoma Murine Models
UHER, Ondřej
2022 - anglický
This dissertation examines the study of intratumoral cancer immunotherapy using a combination of phagocytosis-stimulating ligands and Toll-like receptor ligands (TLR) in murine pancreatic adenocarcinoma and pheochromocytoma murine models. In this study, we show that intratumoral application of the phagocytosis-stimulating ligand Mannan-BAM and three TLR ligands, referred to as MBT therapy, efficiently suppresses tumor growth in more than 83% of mice bearing murine melanoma. However, in aggressive pancreatic adenocarcinoma and pheochromocytoma murine models, such a combination is inefficient and must be combined with an agonistic anti-CD40 antibody, referred to as MBTA therapy, to achieve complete eradication of the tumor. We show that complex intratumoral MBTA therapy can systemically increase the recruitment of innate immune cells followed by activation of adaptive immune cells not only in treated tumors but also in distal non-treated lesions, resulting in the reduction of tumor growth and prolonged survival of treated mice. Taken together, these findings highlight the effect of MBTA therapy and the potential to optimize this therapeutic approach for future use in clinical trials as a treatment for metastatic cancers. This dissertation examines the study of intratumoral cancer immunotherapy using a combination of phagocytosis-stimulating ligands and Toll-like receptor ligands (TLR) in murine pancreatic adenocarcinoma and pheochromocytoma murine models. In this study, we show that intratumoral application of the phagocytosis-stimulating ligand Mannan-BAM and three TLR ligands, referred to as MBT therapy, efficiently suppresses tumor growth in more than 83% of mice bearing murine melanoma. However, in aggressive pancreatic adenocarcinoma and pheochromocytoma murine models, such a combination is inefficient and must be combined with an agonistic anti-CD40 antibody, referred to as MBTA therapy, to achieve complete eradication of the tumor. We show that complex intratumoral MBTA therapy can systemically increase the recruitment of innate immune cells followed by activation of adaptive immune cells not only in treated tumors but also in distal non-treated lesions, resulting in the reduction of tumor growth and prolonged survival of treated mice. Taken together, these findings highlight the effect of MBTA therapy and the potential to optimize this therapeutic approach for future use in clinical trials as a treatment for metastatic cancers.
Klíčová slova:
intratumoral; immunotherapy; cancer; pancreatic adenocarcinoma; pheochromocytoma
Plné texty jsou dostupné v digitálním repozitáři JČU.
Study of Cancer Immunotherapy Mechanisms in Pancreatic Adenocarcinoma and Pheochromocytoma Murine Models
This dissertation examines the study of intratumoral cancer immunotherapy using a combination of phagocytosis-stimulating ligands and Toll-like receptor ligands (TLR) in murine pancreatic ...
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