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Eye evolution and development: an insight from jellyfish and mouse
Růžičková, Jana ; Kozmik, Zbyněk (advisor) ; Jindra, Marek (referee) ; Markoš, Anton (referee)
I. AIMS OF THE STUDY Vision is one of the most crucial senses in higher vertebrates and perhaps the most important sense for humans. The eye morphogenesis has been studied for a long time and especially in the last two decades to address the function of individual genes duing eye development became one of the most interesting topic. Although most of our knowledge about the genetic program underlying eye formation comes from vertebrates, valuable new information about eye evolution has recently been obtained by studies of cnidaria. Therefore elucidation of the biological role and function of eye components of jellyfish Tripedalia cystophora will enhance our knowledge of specific aspects of both eye evolution and development. Specific aims of my PhD thesis were as follows: 1. to describe a new crystallin gene in jellyfish Tripedalia cystophora with respect to the evolution of its regulatory sequences; 2. to characterize genes required for the assembly of camera-type eyes in jellyfish Tripedalia cystophora; 3. to study the role of Wnt/β-catenin during lens induction and formation by employing a new mouse tissue-specific Cre-line; 4. to investigate the functional properties of jellyfish PaxB by expressing it in the developing lens and retina of transgenic mice. 6
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Organic codes and memories
Švorcová, Jana ; Markoš, Anton (advisor) ; Brábek, Jan (referee)
5 Abstract The backgrounds of Marcello Barbieri's semantic biology and the semiotic biology are confronted in the issue of autonomy of living systems. In the place of an interpreter in Pierce's triad, in Barbieri's case there stands a code. Although both concepts attribute important status to the meaning in biology (which is left out outside the scope of semiotic tradition), both concepts are by definition different in the way of apprehension the nature of living systems and of basic biological ideas. Codes are considered to have fundamental status in Barbieri's concept. From this point of view the analysis of histone code hypothesis seems to be appropriate. Can we say (according to our today's scientific knowledge) that histone code truly fulfills demands of Barbieri's concept of codes? Another Barbieri's idea of epigenesis functioning on the basis of biological memory can be unfolded not only thanks to analysis of the phylotypic stage's role, but also by similar analysis of the homeotic genes' role in morphogenesis of vertebrates, because even these genes can be regarded as biological memory of species. These analyses will lead us step by step to the negation of the thesis "cultura contra natura".
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Morphogenesis of the bacterial colonies and their mutually influencing
Rieger, Tomáš ; Markoš, Anton (advisor) ; Rulík, Martin (referee) ; Kuthan, Martin (referee)
This thesis follows previous works of our group (Rieger T. et al., 2008; Cepl J. et al., 2010 and Patkova I. et al., 2012), where we focused on the morphology of the bacterial colonies Serratia marcescens and its variety caused by changing of the inoculation conditions on nutrient agar. When bacterial colonies S. marcescens are grown on nutrient agar enriched with glucose isolated enough from other colonies in its living space, it can form coloured structured colonies, which we named morphotype "fountain" (F). This morpotype becomes ideal for following studies of mutual influencing of the bacterial colonies, because of its ability of pigmentation change or structure loss caused by altering surrounding inoculation conditions. We noticed in normal sowed agar plates, that bacterial colonies, which grows in the close distance with other colonies develop their pigmentation sooner, than colonies, that grows more isolated. We studied how is this influencing happening and what are the necessary conditions for it. We proved, that different species of bacterial macrocolonies (S. marcescens - morphotype (M), S. rubidea and E. coli) emits into the nutrient agar informative signal, which makes the recipient colonies S. marcescens reacts on this signal with the same manner (X structure). It looks, that this is...
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Evolution of light detection in chordates
Pergner, Jiří ; Kozmik, Zbyněk (advisor) ; Markoš, Anton (referee) ; Musilová, Zuzana (referee)
Light detection is one of the crucial abilities of all animals. The light cues are important e.g. for maintaining of circadian rhythms, regulation of spawning cycles, changes of pigmentation and arguably most importantly for vision. Most animals detect light by opsins, members of the G protein coupled receptors superfamily. Amphioxus belongs to earliest branching chordate clade, cephalochordates. Thanks to their phylogenetic position, physiology and morphology, cephalochordates became the most relevant model organism for understanding the evolutionary origins of vertebrate specific traits. Amphioxus evince various reactions to light throughout its development. In the presented thesis light detecting systems of amphioxus were studied thoroughly. More specifically characterization of the opsin gene repertoire of two amphioxus species Branchiostoma floridae and Branchiostoma lanceolatum and their comparison with opsins from other animals is presented. In addition, remarkable similarity on the gene expression level between one of amphioxus visual organs, so called frontal eye, and neurons and retinal pigmented epithelium in vertebrate retina was shown. These data confirm the long time ago proposed homology between amphioxus frontal eye and vertebrate lateral eyes. Taken together all the presented data...
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Transgenerational Epigenetic Inheritance in Mammals
Dostálová, Veronika ; Švorcová, Jana (advisor) ; Markoš, Anton (referee)
Transgenerational epigenetic inheritance in mamals is a widely discussed topic in today's biology. Epigenetic modifications are molecules that play a crucial role in regulation of gene transcription. Epigenetic modifications regulate another epigenetic modification's establishment. The extrinsic and the intrinsic cellular or organismal environment is involved within the establishment of epigenetic state. The molecules involved in epigenetic processes are able to regulate gene transcription in reaction to the environment and therefore these molecules partly shape the phenotype. Most importantly, epigenetic processes are affected by cellular or organismal history. A question emerges: Are these molecules able to transfer information through germline to subsequent generations? Does transgenerational epigenetic inheritance in mammals exist? Experimental data show it is so. What consequences this can mean in our understanding of evolution? Powered by TCPDF (www.tcpdf.org)
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The phenomenon of symbiosis and its importance to theoretical biology
Lhotský, Josef ; Markoš, Anton (advisor) ; Neustupa, Jiří (referee) ; Krajčovič, Juraj (referee)
7 Abstract Close physical interspecific associations called symbioses are central for understanding both evolution and interactions of all branches of living creatures, as well as shaping the Earth's physical features - in other words, they are essential for understanding the nature of whole biosphere. Symbiotic research takes place in some variation in all fields of biology, and since the nature of the phenomenon apparently has a fundamental importance as an exceptional underlying & unifying scheme, there is growing need for appropriate theoretical analysis. Here I discuss the theoretical frame, definition and history of the concept of symbiotic interactions and its significance and use in theoretical biology. Keywords: symbiosis, life, microorganisms, evolution, metaphors and models
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