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Refractive index gradient in the cubozoan eye: gene expression analysis
Jonášová, Kristýna ; Kozmík, Zbyněk (advisor) ; Markoš, Anton (referee)
Lenses are spread through animal kingdom as an improvement of different eye types. Despite conservation of some key regulators and shared use of photopigment opsin, eyes and their lenses develop by variable mechanisms impeaching their monophyletic origin. Tripedalia cystophora (T. c), a cubozoan jellyfish, is an emerging new model for studying eye evolution. The presence of advanced lens-containing eyes (firstly incident within metazoans in this phylum of Cnidaria), the two types of lesser eyes, the use of pax gene and vertebrate type of phototransduction cascade for eye establishment make this jellyfish an useful tool for comparing eye development and different evolutionary strategies. We focused on the lenses of T.c. and studied formation of their refractive index gradient to reveal its mechanism. Using new antibodies raised against J1 and J2 crystallins (proteins of the T. c. lens), TEM and histology we found that graded refractive index is of protein origin and formed by unequal accumulation of proteins (particularly J1 and J2 crystallins) in different layers of the lens. We have shown that J1 crystallin occurs also in the lesser eyes (ocelli) suggesting how the lens mass can evolved. The synthesis of J2 crystallin in lens development has been examined. Furthermore we have prepared J2 crystallin fused...
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Anthropomorphization in Communication with Nonhuman Entities
Uhlíř, Vilém ; Stella, Marco (advisor) ; Markoš, Anton (referee)
In this thesis I pursue a critical summary of the so-called "talking animals" projects, wherein the researchers tried to train their animal subjects to perform "linguistic" feats. Considering both the fundamental dissilimarity of the projects and the uniformity of their results, I am lead to conclude that the shortcoming was that of the students - the animals, and not that of the teachers. Failure of the animal projects points mainly to the fact, that a core feature of language is missing in the pseudolinguistic feats of the animals that which is missing is the hierarchical recursive syntax. I conclude that no animal has had likely adopted the open, unbounded, hierarchically recursive system that allows us, quite literally, to express anything. Linguistic data that I considered indicates that language is most likely an inborn neural specialization of H. spaiens. All the available facts considered manage to show that the pseudolinguistic feats of the "talking" animals are most likely caused by a great plasticity of general cognition. General cognition has the capacity to virtually simulate (although imperfectly) certain aspects of human neural linguistic specialization. Neural linguistic specialization in H. sapiens is an evolutionary discontinuity, whereas the general cognition plasticity is...
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Evolution of hydrogenosomes: adaptation of free living protists Mastagamoeba balamuthi and Naegleria gruberi to oxygen-poor environment
Nývltová, Eva ; Tachezy, Jan (advisor) ; TIELENS, Aloysius Gerard Marie (referee) ; Markoš, Anton (referee)
Various protists from different eukaryotic groups are able to live in the oxygen-poor niches. Their metabolic adaptation to anaerobiosis is usually associated with loss of the typical mitochondrial functions, including the tricarboxylic acid cycle and oxidative phosphorylation. Anaerobic forms of mitochondria generate ATP exclusively by the substrate level phosphorylation in the hydrogen-producing hydrogenosomes, or the ATP synthesis is completely lost as observed in mitosomes. Consequently, the proteomes of such organelles are considerably reduced. It is a question of debate whether the anaerobic forms of mitochondria evolved directly from premitochondrial organelles that might be present in ancient anaerobic eukaryotes or during the secondary adaptation of aerobic eukaryotes to anaerobic niches. The protist from super group Amoebozoa, Mastigamoeba balamuthi, is very attractive for study of mitochondria evolution, because it is closely related with two very different organisms: (i) the aerobic, free-living slime molds such as Dictyostelium that possesses classical aerobic mitochondria, as well as (ii) the anaerobic parasite Entamoeba histolytica that contains mitosomes, the most reduced form of mitochondria. The mitochondria derived organelles in anaerobic, free-living M. balamuthi could represent...
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Symbiosis as a model for a new biology
Lhotský, Josef ; Markoš, Anton (advisor) ; Černý, Robert (referee)
Contemporary biology belongs among the most diversified sciences; yet one of its most fundamental and controversial questions is surprisingly: "What is life?". The aim of this study is to point out that biology is special among other natural sciences because its need of the notion of meaning. Meaning takes the central position in the biological rea-soning. Compared to other sciences, biology has to reflect the dimension of information and its interpretation: language-like properties, communication and interpretation belong to the basic characteristics of life. In spite of the fact, most contemporary theories of evo-lution deny active participation of living beings on the very process - living being come out of its description as puppets or zombies controlled by external forces. As a remedy from such a situation, biology should start with a new model for living entities. A bene-ficial methapor seems to be that of natural languages, i.e. an analogy between a net of historical interactions and conventional ways of interpretation of meaning in (i) living entities and (ii) in system of natural languages. I consider as the most appropriate biolo-gical systems for modeling of such a network of symbiotic interactions, i. e. the pheno-menon of symbiosis and especially symbiogenesis. Keywords: life,...
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Organic memory in embryonic development
Švorcová, Jana ; Markoš, Anton (advisor) ; Černý, Robert (referee) ; Kull, Kalevi (referee)
The submitted thesis deals with the topic of organic memory, its definition and function, as well as its conceptions from various historical points of view. I use the term "organic memory" in respect to some authors who have previously dealt with this subject (Elsasser 1987, Otis 1994, Barbieri 2003) and also as a term by which to represent a kind of memory distinct from neuronal/cerebral memory. The general memory metaphors (in the case of neuronal memory) are essentially connected with terms such as storage, matrix, or place. For rather materialistic conception of memory, it is also symptomatic that different states such as emotions or mental faculties can be concretely localized in the brain tissue. On the contrary, some philosophers described memory as a primarily temporal entity without connection to place or matter. The question of organic memory was already vivid in 19th century biology, linked to Lamarckian philosophy (Hering 1870, Haeckel 1876, Butler 1910). The organic memory ideas floundered between vitalistic and rather materialistic conceptions: the first attributed some psychological features to cells or memory particles; the second was based on physics or in Cartesian doctrine, and described memory as essentially localized as a kind of storage of traces or patterns of physical waves....
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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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