Národní úložiště šedé literatury

Ecology of alpine plants at their uppermost limit in the Himalayas
CHLUMSKÁ, Zuzana
2022 - English This dissertation studies the key abiotic factors and plant characteristics that influence the performance of the highest growing herbaceous alpine plants in Ladakh, Western Himalayas, and examines vegetation changes likely associated with climate change. The study site, located in the Rupshu region of eastern Ladakh, hosts some of the world´s highest-growing angiosperm plant species that occur above 6000 m a.s.l. The gentle slopes characteristic for the region, resulting in long elevational gradients, are particularly suitable for studying plant adaptations to the harsh dry and cold environment typical of whole Ladakh. The study presents novel insights into the causes of plant elevation limits and the direction of the vegetation shifts related to climate change at the very edge of the existence of angiosperms. Keywords: alpine plants; herbaceous plants; Western Himalayas; high elevation; elevational distribution limits; climate change; nonstructural carbohydrates Available in the Digital Repository of University of South Bohemia. Ecology of alpine plants at their uppermost limit in the Himalayas

This dissertation studies the key abiotic factors and plant characteristics that influence the performance of the highest growing herbaceous alpine plants in Ladakh, Western Himalayas, and examines ...

CHLUMSKÁ, Zuzana
Jihočeská univerzita v Českých Budějovicích, 2022

Evolution and Phylogeny of Mesozoa
DRÁBKOVÁ, Marie
2022 - English 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. Keywords: Mesozoa; Dicyemida; Orthonectida; Phylogenomics; Population genetics; Marine biology; Parasites Available in the Digital Repository of University of South Bohemia. 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 ...

DRÁBKOVÁ, Marie
Jihočeská univerzita v Českých Budějovicích, 2022

Aplikované aspekty kryokonzervace rybích spermií
HOROKHOVATSKYI, Yevhen
2018 - English Fish sperm cryopreservation becomes highly attractive due to increasing number of potential applications and it has been considerably developed over the past decades. Cryopreservation of fish sperm is expected to improve the broodstock management in hatcheries, simplify hybridization and selective breeding, and serve as a useful tool for biodiversity and conservation of endangered species programs. Nevertheless, its status nowadays is highly contentious due to absence of specific techniques and standardization in the developed protocols. Moreover, the heterogeneity of cryoresistance in sperm of some fish individuals and, strong impairment of the sperm quality and survival after cryopreservation, to date, present some challenges inhibiting wide applicability of this approach. Therefore, a better understanding of the mechanisms of spermatozoa cryo-injuries and the development of new and more effective methods for cryopreservation of fish sperm are of primary importance. In the current work, the causes of individual variability in sperm cryoresistance, influence of cryopreservation process on sperm quality parameters regarding application of uncontrolled cooling devices were investigated. One of the study outputs is the founding the possible causes of sperm cryoresistance heterogeneity in common carp (Cyprinus carpio) males. As a result, a negative correlation between changes in the contents of major lipid classes and sperm motility after cryopreservation was found. In particular, the increased level of phospholipid, cholesterol and free fatty acid in samples with low post-thaw motility percentage were observed and related to decrease in sperm cryoresistance in common carp sperm. In the investigation of the consequence of the application of uncontrolled cooling devices on post-thaw sperm parameters of sterlet sperm, it has been shown that sterlet sperm could be cryopreserved by both Styrofoam box and dry shipper devices studied. However, due to inability to precisely control cooling process in these devices, the cooling conditions can be changed by varying straw number during freezing in Styrofoam box or by straw position during freezing in dry shipper. As a consequence, these changes shift the optimal freezing rates needed for successful sturgeon sperm cryopreservation resulting in decrease in post-thaw sperm motility and fertilization ability. These results suggest the way of standardization of fish sperm cryopreservation protocols by selecting appropriate straw number or straws position when uncontrolled cooling devices are used. Finally, to explore the cryopreservation effects on fish spermatozoa, the Percoll density gradient centrifugation technique was elaborated and applied for the first time to sterlet (Acipenser ruthenus) sperm. That technique allows to select and analyse only the sperm population that survived cryopreservation procedure and saved high motility parameters. It was found that this spermatozoa subpopulation possesses minimal changes in protein profile in comparison to native sperm. Moreover, the differences in many proteins which were found in sperm suspension after cryopreservation without separation is related to the presence of non-viable and sperm wreckage subpopulations in the frozen-thawed sperm suspension. Collectively, all of these detected changes in sperm motility parameters, viability, and protein profiles of viable spermatozoa after freeze-thaw process suggest some explanations for the mechanism responsible for cryodamage of sperm and provides the background for further development of an efficient cryopreservation protocols. However, it should be also further studied if the Percoll separation technique could serve as a useful tool for both better understanding of non-lethal sperm cryodamages and improvement of assisted reproduction practice in sturgeon species. Kryokonzervace rybích spermií se stala velmi atraktivní kvůli rostoucímu počtu možných aplikací a v posledních desetiletích se značně rozvinula. Od kryokonzervace spermatu ryb se očekává, že zlepší management v líhních, zjednoduší hybridizaci a selektivní chov a poslouží jakožto užitečný nástroj pro biodiverzitu a záchranné programy ohrožených druhů. Kromě toho heterogenita kryorezistence spermií u některých individuálních ryb a silné narušení kvality spermatu a přežití po kryokonzervaci představuje určitou výzvu a brání širší aplikovatelnosti tohoto přístupu. Navíc, heterogenita kryorezistence u spermatu některých jedinců a silné narušení kvality spermatu a jeho přežití po kryokonzervaci představuje dnes určitou výzvu a brání širšímu uplatnění tohoto přístupu. Proto je primárně důležité jednak lepší porozumění mechanismům kryo poškození a jednak vývoj nových a efektivnějších metod pro kryokonzervaci rybího spermatu. V této práci byly zkoumány příčiny individuální variability u kryo odolnosti rybího spermatu a vliv procesu kryokonzervace na parametry kvality spermatu v souvislosti s aplikací nekontrolovaných chladicích zařízeních. Jedním z výstupů této studie je nalezení možných příčin heterogenity kryokonzervace spermií u mlíčáků kapra obecného (Cyprinus carpio). Výsledkem toho byla nalezena negativní korelace mezi změnami v obsahu hlavních lipidových skupin a motility spermatu po kryokonzervaci. Zvláště byla pozorována zvýšená hladina fosfolipidů, cholesterolu a volných mastných kyselin u vzorků s nízkým procentem motility po rozmražení spojená se sníženou kryorezistencí u spermatu kapra obecného. Při zjišťování důsledků aplikace nekontrolovaných chladicích zařízeních na parametry spermií po rozmrazení bylo zjištěno, že sperma jesetera malého může být zamraženo pomocí obou studovaných nástrojů tj. pomocí polystyrenové krabice i suchého přepravního kontejneru. Nicméně kvůli nemožnosti přesně řídit proces ochlazování v těchto dvou zařízeních mohou být chladící podmínky změněny rozdílným množstvím pejet v polystyrenové krabici během mrazení nebo pozicí pejety v suchém přepravním kontejneru. Jako důsledek tyto změny posunují optimální rychlost mrazení potřebnou pro úspěšnou kryokonzervaci spermatu jesetera malého, což vede k poklesu motility spermatu a schopnosti oplození po následném rozmražení. Tyto výsledky naznačují způsob standardizace protokolů kryokonzervace rybího spermatu pomocí volby vhodného množství či pozice pejet, pokud jsou využívány nekontrolovaná chladící zařízení. Nakonec, k prozkoumání účinků kryokonzervace na rybí sperma byla rozpracována technika centrifugace s hustotním gradientem pomocí Percollu a poprvé aplikována na spermie jesetera malého (Acipenser ruthenus). Tato technika umožňuje vybírat a používat pouze populaci spermatu, která přežila proceduru kryokonzervace spermatu, a zároveň zachovává vysoké parametry motility. Bylo zjištěno, že tato subpopulace spermatu vykazuje minimální změny proteinového profilu ve srovnání s čerstvým spermatem. Navíc, rozdíly v mnoha proteinech, které byly nalezeny v suspenzi spermií po zmražení bez separace, jsou spojené s přítomností subpopulací nežádoucích neživotaschopných spermií ve zmražené-rozmražené suspenzi spermatu. Souhrnně, všechny tyto detekované změny v parametrech motility spermatu, jeho životaschopnosti a proteinového složení životaschopného spermatu po zmražení a rozmražení naznačují některé vysvětlení pro mechanismy odpovědné za kryo poškození spermatu a poskytují pozadí pro další vývoj účinných protokolů kryokonzervace. Nicméně by mělo být dále zkoumáno, jestli by separační technika pomocí Percollu mohla sloužit jakožto užitečný nástroj pro lepší porozumění neletálnímu kryo poškození a zlepšení praktiky asistované reprodukce u jeseterů. Keywords: kryokonzervace rybího spermatu; kryoresistence; chladící zařízení; rychlost zmrazování; kryoprotektivní vliv; životaschopnost spermatu; oplodnění; obsah tuků; proteom; separace pomocí Percollu Available in the Digital Repository of University of South Bohemia. Aplikované aspekty kryokonzervace rybích spermií

Fish sperm cryopreservation becomes highly attractive due to increasing number of potential applications and it has been considerably developed over the past decades. Cryopreservation of fish sperm is ...

HOROKHOVATSKYI, Yevhen
Jihočeská univerzita v Českých Budějovicích, 2018

Biosynthesis of chlorophyll-binding proteins in cyanobacteria
BUČINSKÁ, Lenka
2019 - English In oxygenic phototrophs, the photosynthetic machinery is located in thylakoid membrane (TM), a specialized endogenous membrane system. How TM are synthesized remains however mostly unknown. The aim of this thesis was to clarify a link between the synthesis of chlorophyll (Chl)-binding proteins, the main protein component of TM, and the formation of TM system in the model cyanobacterium Synechocystis PCC 6803. During the project, the analysis of TM under various growth conditions and in Chl-deficient mutants has demonstrated that a sufficient amount of de novo produced Chl molecules is crucial for the TM biogenesis. Particularly, the synthesis of the photosystem II subunit CP47 and trimeric photosystem I appeared to be sensitive to a shortage in de novo made Chl molecules. Interestingly, a specialized ribosome-binding protein (Pam68) has been identified to facilitate the insertion of Chl molecules into CP47. The synthesis of Chl-proteins and the biogenesis of TM have been further explored in cells recovering from long-term nitrogen depletion. Using this approach, it was possible to identify a large structure in the cell cytosol, which is very likely the site of TM biogenesis, and to correlate the appearance of this structure with the restored biogenesis of Chl-binding proteins. In oxygenic phototrophs, the photosynthetic machinery is located in thylakoid membrane (TM), a specialized endogenous membrane system. How TM are synthesized remains however mostly unknown. The aim of this thesis was to clarify a link between the synthesis of chlorophyll (Chl)-binding proteins, the main protein component of TM, and the formation of TM system in the model cyanobacterium Synechocystis PCC 6803. During the project, the analysis of TM under various growth conditions and in Chl-deficient mutants has demonstrated that a sufficient amount of de novo produced Chl molecules is crucial for the TM biogenesis. Particularly, the synthesis of the photosystem II subunit CP47 and trimeric photosystem I appeared to be sensitive to a shortage in de novo made Chl molecules. Interestingly, a specialized ribosome-binding protein (Pam68) has been identified to facilitate the insertion of Chl molecules into CP47. The synthesis of Chl-proteins and the biogenesis of TM have been further explored in cells recovering from long-term nitrogen depletion. Using this approach, it was possible to identify a large structure in the cell cytosol, which is very likely the site of TM biogenesis, and to correlate the appearance of this structure with the restored biogenesis of Chl-binding proteins. Keywords: Synechocystis PCC 6803; chlorophyll-binding proteins; chlorophyll biosynthesis; thylakoid membrane; biogenesis center; assembly factors; Pam68 Available in the Digital Repository of University of South Bohemia. Biosynthesis of chlorophyll-binding proteins in cyanobacteria

In oxygenic phototrophs, the photosynthetic machinery is located in thylakoid membrane (TM), a specialized endogenous membrane system. How TM are synthesized remains however mostly unknown. The aim of ...

BUČINSKÁ, Lenka
Jihočeská univerzita v Českých Budějovicích, 2019

Genome analysis of the haloalkaliphilic bacterium Rhodobaca barguzinensis
KOPEJTKA, Karel
2019 - English This PhD thesis presents results of a research focussed on the evolution of phototrophy in the bacterial order Rhodobacterales with a special regard to its haloalkaliphilic representatives. The photoheterotrophic bacterium Rhodobaca barguzinensis alga05 was used as an organism of choice. Its phylogeny, genome organization, and metabolic potential was characterized. The main result of the thesis is that phototrophy is a genuine trait among the haloalkaliphilic representatives of the Rhodobacter-Rhodobaca group inside the Rhodobacterales clade. This PhD thesis presents results of a research focussed on the evolution of phototrophy in the bacterial order Rhodobacterales with a special regard to its haloalkaliphilic representatives. The photoheterotrophic bacterium Rhodobaca barguzinensis alga05 was used as an organism of choice. Its phylogeny, genome organization, and metabolic potential was characterized. The main result of the thesis is that phototrophy is a genuine trait among the haloalkaliphilic representatives of the Rhodobacter-Rhodobaca group inside the Rhodobacterales clade. Keywords: Anoxygenic photosynthesis; genome evolution; haloalkaliphiles; horizontal gene transfer; photosynthesis gene cluster; Rhodobacteraceae. Available in the Digital Repository of University of South Bohemia. Genome analysis of the haloalkaliphilic bacterium Rhodobaca barguzinensis

This PhD thesis presents results of a research focussed on the evolution of phototrophy in the bacterial order Rhodobacterales with a special regard to its haloalkaliphilic representatives. The ...

KOPEJTKA, Karel
Jihočeská univerzita v Českých Budějovicích, 2019

Study of adipokinetic hormone role in insects stressed by entomopathogenic nematodes
IBRAHIM, Emad Ahmed Sayed
2019 - English In this thesis, the effect of infection elicited by entomopathogenic nematodes (EPNs) Steinernema carpocapsae on Pyrrhocoris apterus and Drosophila melanogaster models were evaluated, and a role of adipokinetic hormones (AKHs) during the infection was characterized. These were monitored by determination of mortality, and various biochemical and physiological characteristics such as AKH levels both in the central nervous system (CNS) and in hemolymph, AKH gene expression in CNS, level of anti-oxidative stress markers, general metabolism and level of nutrients in normal and genetically modified insects. At P. apterus the mortality tests revealed that application of AKH increases the efficacy of EPN treatment. This result was confirmed using the firebugs with AKH receptor deficiency. Further, the increase of AKH expression and AKH levels in CNS and hemolymph seemed to be coordinated after the nematode treatment. At the D. melanogaster model also, the effect of adenosine into the above-mentioned characteristics was included. For this, mutants in AKH (AHK1), adenosine receptor (AdoR1) genes, and in both these genes together (AHK1 AdoR1 double mutant) were employed. Altogether, the results confirmed the involvement of AKH, and partially also adenosine into the antistress defense reactions elicited by the nematobacterial infection. Finally, the last part of the study was focused on examination of the vitellogenin (Vg) role in the defense reaction in firebug body P. apterus affected by two entomopathogenic organisms, the nematode S. carpocapsae and the fungus Isaria fumosorosea. The results revealed that Vg proteins play an important role in the defense against both types of the infections and are also able to kill entomopathogenic bacteria Xenorhabdus nematophila, that are symbionts of S. carpocapsae and that increase toxicity of this nematode. In this thesis, the effect of infection elicited by entomopathogenic nematodes (EPNs) Steinernema carpocapsae on Pyrrhocoris apterus and Drosophila melanogaster models were evaluated, and a role of adipokinetic hormones (AKHs) during the infection was characterized. These were monitored by determination of mortality, and various biochemical and physiological characteristics such as AKH levels both in the central nervous system (CNS) and in hemolymph, AKH gene expression in CNS, level of anti-oxidative stress markers, general metabolism and level of nutrients in normal and genetically modified insects. At P. apterus the mortality tests revealed that application of AKH increases the efficacy of EPN treatment. This result was confirmed using the firebugs with AKH receptor deficiency. Further, the increase of AKH expression and AKH levels in CNS and hemolymph seemed to be coordinated after the nematode treatment. At the D. melanogaster model also, the effect of adenosine into the above-mentioned characteristics was included. For this, mutants in AKH (AHK1), adenosine receptor (AdoR1) genes, and in both these genes together (AHK1 AdoR1 double mutant) were employed. Altogether, the results confirmed the involvement of AKH, and partially also adenosine into the antistress defense reactions elicited by the nematobacterial infection. Finally, the last part of the study was focused on examination of the vitellogenin (Vg) role in the defense reaction in firebug body P. apterus affected by two entomopathogenic organisms, the nematode S. carpocapsae and the fungus Isaria fumosorosea. The results revealed that Vg proteins play an important role in the defense against both types of the infections and are also able to kill entomopathogenic bacteria Xenorhabdus nematophila, that are symbionts of S. carpocapsae and that increase toxicity of this nematode. Keywords: Mortality; Akh gene expression; AKH receptor; Metabolism; RNAi; Pyrrhocoris apterus; Adipokinetic hormone; Adenosine; Drosophila; Oxidative stress; Locomotion; insect; vitellogenin; infection; entomopathogenic nematode; entomopathogenic fungus; antimicrobial activity Available in the Digital Repository of University of South Bohemia. Study of adipokinetic hormone role in insects stressed by entomopathogenic nematodes

In this thesis, the effect of infection elicited by entomopathogenic nematodes (EPNs) Steinernema carpocapsae on Pyrrhocoris apterus and Drosophila melanogaster models were evaluated, and a role of ...

IBRAHIM, Emad Ahmed Sayed
Jihočeská univerzita v Českých Budějovicích, 2019

Assembly and analysis of repeat-rich regions of plant genomes
VONDRAK, Tihana
2022 - English 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. Available in the Digital Repository of University of South Bohemia. 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, ...

VONDRAK, Tihana
Jihočeská univerzita v Českých Budějovicích, 2022

Polyploidizační schopnost jeseterů a její vliv na fitness
HUBÁLEK, Martin
2022 - English Sturgeons (order Acipenseriformes) are considered one of the most ancient groups of fish still present on Earth. The evolution of these 'living fossils' is inherently connected to polyploidization events. Moreover, spontaneously arisen polyploidy has been widely reported in farmed populations of many sturgeon species, and there is also evidence that it randomly occurs in the wild. The persistence of sturgeons for creating polyploid genomes underlines the genome plasticity of these fishes and makes them suitable candidates for polyploid research. However, only a few studies have ever investigated the effects of newly formed polyploidy on fitness or physiology of sturgeons. Broadening the scope of research is of particular interest, since it may shed light on how sturgeon neopolyploids perform in aquaculture and nature, uncover the impact of contemporary polyploidization on sturgeon farming and conservation, and contribute to scientific knowledge regarding the consequences of polyploidy on fish. The second chapter of this thesis introduced an optimized protocol for the creation of biologically triploid populations of sterlet (Acipenser ruthenus) via the second polar body retention (SPBR) achieved by hydrostatic pressure shock. Apart from the presented study, the application of this type of shock in sturgeons has only ever been reported in shortnose sturgeon (Acipenser brevirostrum). Our findings suggested that hydrostatic pressure shock can be more reliable at producing 100% triploids and yield better hatching rates than conventionally used heat shock. Its utilization may thus improve the efficiency in obtaining triploidized progeny of sturgeons. Flow cytometric analysis of relative DNA content in cell nuclei is among the most preferred techniques for the measurement of ploidy levels in sturgeons, but its application has so far been limited to the examination of fresh material. The third chapter of this thesis provided the verified methods for 10-day storage of various types of sturgeon samples - blood, finclip and larva tail tissue. The protocols proposed are easy to use, do not contain centrifugation steps and allow field sampling. The viability and growth of early developmental stages of autopolyploid sterlet kept at both optimal (16 °C) and suboptimal temperatures (10 and 20 °C) were investigated in fourth chapter. The results suggested that irrespective of temperature, biologically triploid sterlet arising from SPBR do not differ from individuals of normal ploidy (normoploids) in terms of survival and growth. The viability of embryos obtained from tetraploidization via the first mitotic division suppression (FMDS) was considerably reduced at optimal temperature and even more so at suboptimal conditions. Biologically tetraploid prelarvae were not able to survive at suboptimal temperatures, assuming their lower thermal tolerance when compared to normoploids or biological triploids. Biological hexaploidy seemed to be lethal, since the individuals obtained from the combined treatment causing both SPBR and FMDS were unable to survive the prelarval period at any temperature. In the fifth chapter of this thesis, the effects of SPBR-induced polyploidy on critical swimming speed, physiology and haematology were investigated using nine-month-old juveniles of two pure sturgeon species, sterlet and Siberian sturgeon (Acipenser baerii), and their reciprocal hybrids. SPBR-induced polyploids of both purebreds and hybrids did not differ from their normoploid counterparts in swimming performance, and the haematological analysis revealed that they were able to fully compensate for having fewer erythrocytes than normoploids in blood haemoglobin and haematocrit. Likewise, the study did not provide any evidence for SPBR-induced polyploidy affecting stress response. These results may indicate that sturgeon polyploids arising from SPBR do not suffer from any substantial physiological limitation and are as fit as their counterparts of normal p Jeseteři (řád Acipenseriformes) jsou považováni za jedny z nejstarobylejších ryb dosud žijících na planetě Zemi. Evoluce těchto "živoucích fosilií" je neodmyslitelně spjata s polyploidizačními událostmi. U chovaných populací mnoha jeseteřích druhů byla navíc pozorována spontánně vznikající polyploidie, která se dle dostupných důkazů náhodně vyskytuje i ve volné přírodě. Přetrvávající sklony jeseterů vytvářet polyploidní genomy zdůrazňují genomovou plasticitu těchto ryb a činí z nich vhodné kandidáty pro výzkum polyploidie. Vlivem indukované nebo spontánně vznikající polyploidie na fitness a fyziologii jeseterů se však doposud zabývalo pouze pár studií. Rozšiřování znalostí v této oblasti má zvláštní význam, neboť může pomoci objasnit, jak neopolyploidní jeseteři prosperují v akvakultuře nebo v přírodě, odhalit vliv současných polyploidizací na chov a konzervaci jeseterů, a prohloubit vědecké poznání důsledků polyploidie pro ryby. Druhá kapitola předkládané práce přináší optimalizovaný protokol pro vytváření biologicky triploidních populací jesetera malého (Acipenser ruthenus) pomocí retence druhého pólového tělíska (RDPT) hydrostatickým tlakem. S výjimkou této práce byla doposud aplikace tohoto typu šoku u jeseterů publikována pouze u jesetera krátkorypého (Acipenser brevirostrum). Na základě zjištění naší studie lze usoudit, že šok hydrostatickým tlakem může být pro produkci 100 % triploidů vhodnější než konvenčně používaný teplý šok, a zároveň vést k dosažení vyšší líhnivosti. S jeho použitím by tedy mohlo být triploidizované potomstvo jeseterů získáváno efektivněji. Měření relativního obsahu DNA v buněčných jádrech průtokovou cytometrií patří mezi nejběžnější metody určování ploidní úrovně jeseterů, její využití bylo však doposud omezeno na analýzu nativního materiálu. Výsledkem práce, popsané ve třetí kapitole, jsou ověřené metody pro desetidenní uchování různých typů jeseteřích vzorků. Navrhované protokoly jsou jednoduše využitelné, neobsahují centrifugace a umožňují terénní vzorkování. Ve čtvrté kapitole byla zkoumána životaschopnost a růst raných vývojových stádií autopolyploidních jeseterů malých v optimální (16 °C) teplotě a teplotách suboptimálních (10 a 20 °C). Její výsledky naznačují, že biologicky triploidní jeseteři malí se od jedinců běžné ploidie (normoplodi) neliší v přežití ani růstu, a to bez ohledu na teplotu. Životaschopnost embryí získaných tetraploidizací prostřednictvím zadržení prvního mitotického dělení (ZPMD) byla naproti tomu výrazně snížena už při inkubaci v optimální teplotě, a ještě výrazněji v teplotách suboptimálních. Biologicky tetraploidní prelarvy nebyly v suboptimálních teplotách schopné přežít, což poukazuje na jejich nižší teplotní toleranci v porovnání s normoploidy a biologickými triploidy. Biologická hexaploidie je u jeseterů zřejmě letální, neboť jedinci získaní z kombinované indukce RDPT a ZPMD nepřežili prelarvální periodu v žádné z testovaných teplot. V páté kapitole této práce byl popsán zkoumaný vliv polyploidie indukované prostřednictvím RDPT na kritickou rychlost plavání, fyziologii a hematologii devítiměsíčních juvenilů dvou čistých jeseteřích druhů, jesetera malého a jesetera sibiřského (Acipenser baerii) a jejich reciprokých hybridů. Z výsledků měření kritické rychlosti plavání vyplynulo, že se RDPT-indukovaní polyploidi obou čistých druhů a hybridů ve své výkonnosti nelišili od normoploidů. Hematologická analýza odhalila, že polyploidi získaní indukcí RDPT byli z hlediska úrovní krevního hemoglobinu a hematokritu schopni plně kompenzovat nižší počet erytrocytů v porovnání s normoploidy. Studie rovněž nepotvrdila, že by RDPT-indukovaná polyploidie ovlivňovala stresovou odpověď. Tyto výsledky naznačují, že polyploidi jeseterů vzniklí z RDPT netrpí žádnou významnou fyziologickou limitací a po stránce fyzické zdatnosti jsou srovnatelní s jejich protějšky běžné ploidní úrovně. Keywords: Chondrostei; polyploidie; triploidie; tetraploidie; hexaploidie; průtoková cytometrie Available in the Digital Repository of University of South Bohemia. Polyploidizační schopnost jeseterů a její vliv na fitness

Sturgeons (order Acipenseriformes) are considered one of the most ancient groups of fish still present on Earth. The evolution of these 'living fossils' is inherently connected to polyploidization ...

HUBÁLEK, Martin
Jihočeská univerzita v Českých Budějovicích, 2022

Formation of Fe-S clusters in the mitochondrion of Trypanosoma brucei
CHANGMAI, Piya
2013 - English This thesis focuses on iron sulfur (Fe-S) cluster biogenesis by the ISC machinery in the mitochondrion of Trypanosoma brucei. Most of proteins in the pathway show conserved functions, while some features are distinct from their counterparts in other organisms. We also show here the essentiality of the ISC machinery in bloodstream stage despite the fact that the parasites contain the rudimentary mitochondrion in this stage. The key player for the ISC export machinery, which is indispensable in the maturation of extra-mitochondrial Fe-S proteins, shows some extraordinary phenomena which may imply the moonlighting function of the protein. I also show preliminary data of an ongoing project concerning a putative heme transporter. The results indicate role in heme uptake of the protein, but further study is required to confirm the function of the protein. This thesis focuses on iron sulfur (Fe-S) cluster biogenesis by the ISC machinery in the mitochondrion of Trypanosoma brucei. Most of proteins in the pathway show conserved functions, while some features are distinct from their counterparts in other organisms. We also show here the essentiality of the ISC machinery in bloodstream stage despite the fact that the parasites contain the rudimentary mitochondrion in this stage. The key player for the ISC export machinery, which is indispensable in the maturation of extra-mitochondrial Fe-S proteins, shows some extraordinary phenomena which may imply the moonlighting function of the protein. I also show preliminary data of an ongoing project concerning a putative heme transporter. The results indicate role in heme uptake of the protein, but further study is required to confirm the function of the protein. Keywords: Fe-S cluster biogenesis; ISC machinery; Fe-S proteins; ISC export machinery; heme Available in the Digital Repository of University of South Bohemia. Formation of Fe-S clusters in the mitochondrion of Trypanosoma brucei

This thesis focuses on iron sulfur (Fe-S) cluster biogenesis by the ISC machinery in the mitochondrion of Trypanosoma brucei. Most of proteins in the pathway show conserved functions, while some ...

CHANGMAI, Piya
Jihočeská univerzita v Českých Budějovicích, 2013

Carbon dioxide transport within the leaf mesophyll: physico-chemical and biological aspects
VRÁBL, Daniel
2013 - English Stomatal conductance and mesophyll conductance for CO2 transport are two key components of diffusive limitations of photosynthesis, since they restrict CO2 flux from the leaf surface to the sub-stomatal cavity and from there to the sites of carboxylation. This thesis summarizes our findings in the field of nature of mesophyll conductance to CO2 transport and its regulation per se and in respect to stomatal conductance. Průduchová a mezofylová vodivost pro transport oxidu uhličitého jsou dvě klíčové komponenty difúzních limitací fotosytnézy, které omezují tok CO2 z povrchu listu až do míst karboxylace. Tato dizertační práce shrnuje výsledky z oblasti podstaty mezofylové vodivosti pro transport CO2, její samostatné regulace a regulace ve vztahu k průduchové vodivosti. Keywords: carbon dioxide; photosynthesis; diffusional limitations; mesophyll conductance; stomatal conductance; water use efficiency Available in the Digital Repository of University of South Bohemia. Carbon dioxide transport within the leaf mesophyll: physico-chemical and biological aspects

Stomatal conductance and mesophyll conductance for CO2 transport are two key components of diffusive limitations of photosynthesis, since they restrict CO2 flux from the leaf surface to the ...

VRÁBL, Daniel
Jihočeská univerzita v Českých Budějovicích, 2013