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Bioluminescence in Dinoflagellates
Zahradníček, Ondřej ; Němcová, Yvonne (advisor) ; Pichrtová, Martina (referee)
Bioluminescence is a relatively widespread phenomenon in nature. A variety of organisms have the ability to emit light. The aim of this bachelor thesis is to summarize the latest findings on bioluminescence in dinoflagellates. These organisms are the most important protist lineage capable of producing light flashes. Indeed, they are responsible for most of the bioluminescence observed in surface the seas and oceans. This bachelor thesis discusses the biochemical reaction of bioluminescence in which the substrate (luciferin) is oxidized in the presence of the enzyme luciferase. The thesis introduces the major species of luminescent dinoflagellates that frequently cause toxic harmful algal blooms. Then the factors affecting the intensity of bioluminescence are discussed. Last but not least, dinoflagellates can use bioluminescence as protection from predators. For example, they may use a flash of light to startle predators or use the flash as a "burglar alarm" to attract predators of their predators. Key words: bioluminescence, luciferin, luciferase, dinoflagellates, light flash
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Danio rerio as a model of serious human diseases
Hason, Martina ; Bartůněk, Petr (advisor) ; Živný, Jan (referee) ; Divoký, Vladimír (referee)
(ENGLISH) Over the last five decades, zebrafish (Danio rerio) has become a useful vertebrate model organism for the field of developmental biology and disease control. Using zebrafish in xenotransplantation studies is becoming more popular and progressed towards drug screening of anti-cancer drugs. Zebrafish are particularly suitable for high-throughput pre-clinical drug screening, due to the small size of embryos and the striking evolutionary conservation of cancer- related pathways between human and zebrafish. The fast, large-scale evaluation of the cancer- drug response in vivo could facilitate progress in personalized cancer therapy. Nevertheless, there is still a lack of methods which would allow for rapid and sensitive evaluation of tumor cell growth to facilitate high-throughput screening of drugs in vivo. In our bioluminescent zebrafish transplantation model, we proposed and validated a new screening platform for pre-clinical drug discovery in zebrafish embryos. In our experiments we used the NanoLuc luciferase, which enabled us to rapidly screen inhibitors of cancer growth in a sensitive and quantitative way with very low background compared to the conventional fluorescence signal. In our screen we evaluated the in vivo drug response of 180 kinase inhibitors in zebrafish embryos...
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Dynamic of PER2 clock protein degradation detected by real time bioluminescence assay in the tissue explant of the circadian clock of mPER2Luc mouse
Stanislavová, Faustýna ; Sumová, Alena (advisor) ; Doležel, David (referee)
Suprachiasmatic nuclei are the main oscillator of circadian rhythms. Using clock genes and their protein products (forming transcription-translation feedback loops), suprachiasmatic nuclei play an important role in the control of many physiological functions. Bioluminescence (the amount of hourly protein PER2) was measured by a method using transgenic organisms. In this work, cycloheximide was used to inhibit proteosynthesis and to subsequently monitor the degradation of PER2 in real time. The protein was then measured in explants of suprachiasmatic nuclei of adult mice, in suprachiasmatic nuclei of fetuses and in placentas. Furthermore, the effects of glycogen synthasykinase 3b inhibitors on the dynamics of PER2 protein degradation were compared. A selective inhibitor CHIR-99021 and a non-specific inhibitor lithium chloride were used. The experiment shows that the CHIR inhibitor slows down protein degradation in all tissues used. In contrast, the effect of a non-specific lithium chloride inhibitor has not been clearly demonstrated. In fetal nuclei, its effect on the dynamics of degradation was slowing, while in adult nuclei, degradation was significantly accelerated. No significant results were observed in placental explants. Research focusing on the influence of these clock genes, respectively...
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Real-time monitoring of cellular processes - current approaches
Švecová, Iva ; Hodný, Zdeněk (advisor) ; Groušl, Tomáš (referee)
This thesis aims to provide an overview of real-time live-cell imaging methods with a focus on the signalling pathways. The first, most thorough section is about fluorescence methods and is followed by sections about bioluminescence and label-free methods. In the fluorescence section, we will at first introduce the types of fluorophores and respective labelling approaches. Subsequently, we will go through the individual techniques, starting with single-fluorophore and FRET biosensors, continuing with kinetic modelling approaches, a FLIM method used to detect changes in the cellular environment, and ending with two methods used to improve the resolution. With each technique, we will shortly explain the working principle and look at the examples at which this method was used. Finally, we will look at the example of live-cell imaging of one signalling cascade.
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Využití bioluminiscenčních, histologických a imunohistochemických technik při studiu lokalizace produktů genové exprese v tkáních hmyzu
PAUCHOVÁ, Lucie
The genes of enzymes catalyzing the bioluminescence reactions are commonly used as reporter genes in molecular biology. These markers are applied especially, in the studies of daily oscillation of gene expression products involved in the circadian clock. Here is reported an improved technique for monitoring the clock gene expression on the single neuron level in the brain of Drosophila melanogaster by using the bioluminescence marker. A part from that another study is focused on localizing a newly identified neuropeptide TEFLa in different developmental stages of firebug Pyrrhocoris apterus. This neuropeptide was detected in the brain of larvae and adults, in the posterior region of the midgut of adults and in the gonades of larvae. Beside that, it was found in the region of amnion closure in embryos. Synthesis of TEFLa in the adults' gut is controlled by the circadian rhythms. Identification of TEFLa distribution helps to uncover the function of this neuropeptide.
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Denní změny intenzity emise fotonu z lidských rukou
Cifra, Michal ; Van Wijk, E. ; Koch, H. ; Bosman, S. ; Van Wijk, R.
Spontaneous ultra-weak photon emission in the visible range was measured on palm and dorsal side of left and right hand by means of a low noise photomultiplier system. To study the dynamics of this photon emission in a 24h period photon emission was recorded in 2h intervals in 5 experiments. Mean photon emission over the 24h period differed both between subjects and hand locations. The fluctuations in photon emission in the course of 24h were more at dorsal sides than palm sides.
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Lidská spontanní emise fotonu v průběhu 24 hodin
Cifra, Michal ; Van Wijk, E. ; Van Wijk, R.
Ultra-weak spontaneous photon emission in visible range from palms and hands of dark-accommodated subjects has been measured every two hours in 5 experiments in the course of 24 hours by means of low-noise photomultiplier. Dorsal sides of the hands show higher fluctuations of photon emission intensity than palmar sides. Cycles of fluctuations of the 1 day, 6-8 hours and 3-4 hours long period have been observed from Fourier analysis of the measured data.
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Dynamika spontánní emise fotonu z lidského těla v průběhu 24 hodin
Cifra, Michal
Spontaneous ultra-weak photon emission in the visible range was measured on palm and dorsal side of left and right hand by means of a low noise photomultiplier system. To study the dynamics of this photon emission in a 24h period photon emission was recorded in 2h intervals in 5 experiments. Mean photon emission over the 24h period differed both between subjects and hand locations. The fluctuations in photon emission in the course of 24h were more at dorsal sides than palm sides.
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