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Multi-component signalling in turtles and squamate reptiles
Brejcha, Jindřich ; Kleisner, Karel (advisor) ; Rehák, Ivan (referee) ; Carazo, Pau (referee)
Multicomponent signals are complex stimuli directed to receptors of only single modality. Colourful ornaments of animals are multicomponent signals. In this thesis I present results of studies on the origin of coloration in turtles and squamate reptiles together with notes on relativistic view of the functionality of animal coloration. The results show that turtle coloration, which have been studied only marginally until now, is shaped by sexual selection. It is shown that turtles share mechanisms of coloration by vertical organization of different pigment cell types together with squamate reptiles. Turtles also produce colour by organization of collagen fibres which share trait with birds and mammals. Mechanisms of body coloration differ dramatically between closely related turtle species studied even though the individual constituting components are shared among these species. On the example of polymorphic lizards, it is shown that qualitative categorical difference between groups of individuals of the same population are maintained based on quantitative changes in pigment contents regulated by ancient loci shared by different species. The turtles and reptiles are valuable source of our knowledge on the evolution of multicomponent visual signalling due to their intriguing composition of skin....
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Regulation of the regular distribution of body covering structures
Zbirovský, Richard ; Soukup, Vladimír (advisor) ; Brejcha, Jindřich (referee)
5 Abstract Vertebrates are characterised by a great diversity of integumentary appendages, such as scales, feathers or hairs, or modifications derived from them. These organs tend to be distributed individually and evenly across the body surface, and the degree of regularity of their organisation may vary between species. The regulation of their formation and regular distribution is determined by epithelial-mesenchymal interactions. Signaling pathways are key components of these interactions, and molecular morphogens such as BMPs, Wnts, FGFs and Shh are their frequent participants. Many mathematical models have been proposed in an attempt to explain the relationships between those morphogens, which lead to the orderly spacing of integumentary appendages, during the process that is also known as patterning. Recently, however, the Turing reaction-diffusion model, consisting of the interplay between activators and inhibitors to achieve a self-organizing, repetitive patterning, has come to the fore again. The aim of this Bachelor thesis is to further explore the role of the Turing mechanism in the regulation and regularity of the distribution of body covering organs. Keywords: vertebrates, Turing, reaction-diffusion mechanism, patterning, feathers, hairs, scales, FGF, BMP, Shh, Wnt
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Diversity of iris coloration during evolution of geckos (Gekkota)
Ozerskyi, Serhii ; Brejcha, Jindřich (advisor) ; Šmíd, Jiří (referee)
Iris is an anatomical structure that performs the function of a diaphragm in the visual system of the eye. It usually occupies most of the visible part of the eye. In addition to the main function - not to let light pass by the pupil, iris can play many different roles due to the great variability of its coloration. Iris can be part of a camouflage or aposematic color, play a different role in intra- or interspecific communication. In some species, its color changes depending on age, season, biological cycles, or even quickly become marked in response to stimuli. Geckos (Gekkota) are distinguished by a particularly large variety of iris color. And in many of them, the iris pattern resembles branching veins. What significance and evolution history this pattern has is of interest. I used various models of evolutionary reconstruction in the R program to study the evolution of veined pattern of coloration of the iris, as well as phylogenetic comparative methods and binary character evolution model to identify its connections with the fusion of life and the contrast in brightness between the eye and the eye ring. It was revealed that the veined pattern is an ancestral condition for geckos and is present in most modern species. Most precisely, the evolution of the vein pattern is described by all rates different...
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Distribution and invasiveness of Trachemys scripta in the Czech Republic
Brejcha, Jindřich ; Šandera, Martin (advisor) ; Gvoždík, Václav (referee)
Biologické invaze jsou jednou z příčin úbytku biodiverzity na Zemi. Zprávně používaná terminologie je nutností pro objektivní hodnocení výskytu nepůvodních druhů. Nepůvodní druh je taxon zavlečený mimo svůj přirozený areál. Naturalizovaný druh je takový taxon, který se vyrovnal s novým prostředím a vytváři na něm pravidelně se rozmnožující populace, jejichž dlouhodobé přežívání je pravděpodobné. Invazivní je takový naturalizovaný taxon, který se šíří a produkuje potomstvo v oblastech vzdálených od místa vysazení. K vyjádření dopadu na životní prostředí a ekonomiku je vhodné užívat zvláštní kategorie jako jsou škodlivý druh či transformers. Pouze národní bohatství a hustota obyvatel jsou statisticky prokazatelné pro předpovídání invazí napříč všemi taxonomickými skupinami ve srovnaní s klimatem, geografickými faktory a charakterem krajiny. Želva nádherná byla v druhé polovině 20.století zavlečena na pět kontinentů světa. V Evropě je v jižních zemích naturalizovaná až invasivní. Na území České republiky je želva nádherná příležitostný nepůvodní druh (casual species), který se zde pokouší o rozmnožování. První zmínky o výskytu želvy nádherné na našem území pocházejí z 60. let 20. století. Na základě publikovaných údajů, ústních sdělení a nepublikovaných písemných údajů byl sestaven seznam 190 záznamů...
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Postnatal Ontogenesis of the Skull of the Pond Slider Turtle (Trachemys scripta)
Čtrnáctová, Lenka ; Brejcha, Jindřich (advisor) ; Soukup, Vladimír (referee)
This thesis focuses on the descriptive analysis of skull morphology of the pond slider turtle (Trachemys scripta elegans). The general approach was an osteological preparation of the skulls and photographic documentation (following standardised procedures) of a larger sample of specimens. The collected data was used as a background for subsequent GMM analyses. Main hypotheses of this project were: 1) the skull of T. s. elegans is sexually dimorphic; 2) the skull of T. s. elegans constitutes of several independent modules. The objective of this thesis was therefore to describe the postnatal ontogenesis of the model taxon and to determine the developmental trends of its cranial structures. It was shown that the skull of T. s. elegans is sexually dimorphic in shape mainly due to differences in allometric growth. These differences probably reflect different nutritional requirements. The skull of T. s. elegans is formed out of four modules. These are: facial, central, basicranial, and possibly also zygomatic-pterygoideal modules.
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Methods for storing and archiving zoological tissue collections, and identification based on DNA barcoding
Aghová, Tatiana ; Benda, Petr ; Brejcha, Jindřich ; Dolejš, Petr ; Kyralová, Eva ; Mlíkovský, Jiří ; Moravec,Jiří ; Šanda, Radek ; Štundl, Jan ; Tkoč, Michal ; Vondráček, Dominik
Fulltext:  PDF; PDF; PDF; PDF
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Multi-component signalling in turtles and squamate reptiles
Brejcha, Jindřich ; Kleisner, Karel (advisor) ; Rehák, Ivan (referee) ; Carazo, Pau (referee)
Multicomponent signals are complex stimuli directed to receptors of only single modality. Colourful ornaments of animals are multicomponent signals. In this thesis I present results of studies on the origin of coloration in turtles and squamate reptiles together with notes on relativistic view of the functionality of animal coloration. The results show that turtle coloration, which have been studied only marginally until now, is shaped by sexual selection. It is shown that turtles share mechanisms of coloration by vertical organization of different pigment cell types together with squamate reptiles. Turtles also produce colour by organization of collagen fibres which share trait with birds and mammals. Mechanisms of body coloration differ dramatically between closely related turtle species studied even though the individual constituting components are shared among these species. On the example of polymorphic lizards, it is shown that qualitative categorical difference between groups of individuals of the same population are maintained based on quantitative changes in pigment contents regulated by ancient loci shared by different species. The turtles and reptiles are valuable source of our knowledge on the evolution of multicomponent visual signalling due to their intriguing composition of skin....
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Postnatal Ontogenesis of the Skull of the Pond Slider Turtle (Trachemys scripta)
Čtrnáctová, Lenka ; Brejcha, Jindřich (advisor) ; Soukup, Vladimír (referee)
This thesis focuses on the descriptive analysis of skull morphology of the pond slider turtle (Trachemys scripta elegans). The general approach was an osteological preparation of the skulls and photographic documentation (following standardised procedures) of a larger sample of specimens. The collected data was used as a background for subsequent GMM analyses. Main hypotheses of this project were: 1) the skull of T. s. elegans is sexually dimorphic; 2) the skull of T. s. elegans constitutes of several independent modules. The objective of this thesis was therefore to describe the postnatal ontogenesis of the model taxon and to determine the developmental trends of its cranial structures. It was shown that the skull of T. s. elegans is sexually dimorphic in shape mainly due to differences in allometric growth. These differences probably reflect different nutritional requirements. The skull of T. s. elegans is formed out of four modules. These are: facial, central, basicranial, and possibly also zygomatic-pterygoideal modules.
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The Mimicry of Coral Snakes and King Snakes and the Approaches of Adolf Portmann
Čtrnáctová, Lenka ; Figura, Roman (advisor) ; Brejcha, Jindřich (referee)
The problem of the supposedly mimetic relationship between some species of king snakes and coral snakes is rather scattered in literature and opinions on it vary greatly. In this work, I focus on summarizing and generalizing the existing pieces of knowledge about the colouration of these snakes and its consequences for evolutionary biology - neodarwinistic and especially portmannistic. In other words, natural selection does not solve all the questions and in this case in particular, it is obvious that mimesis interests not only biologists, but also mathematicians, chemists, physicists and philosophers. All of these are trying to find the answer to whether mimesis in these snakes is actually occurring and what would be the purpose of such colouration if it is not. Adolf Portmann is very clear on this subject: organisms show their inner properties on the outside as a means to self-present. The specific appearance is not determined and it does not have to have any adaptive value at all.
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Naturalization of the pond slider (Trachemys scripta) in the Czech Republic
Brejcha, Jindřich ; Šandera, Martin (advisor) ; Vojar, Jiří (referee)
Shrnutí Opatření ochrany přírody proti nepůvodním druhům jsou nejefektivnější zejména v brzkých fázích invaze, kdy jsou postižena pouze malá území. Modelování rozšíření druhů (SDM) je moderní nástroj pro analýzu a komparaci podmínek v geografickém prostoru. V práci bylo užíváno korelačních přístupů SDM pro deskripci a predikci realizované niky Trachemys scripta na území České republiky s využitím Grinelovských tříd proměnných. Výsledky modelů BIOCLIM a MaxEnt ukázaly, že rozsah hodnot výskytu T. scripta v přírodních podmínkách v ČR tvoří okraj potenciálního rozšíření v Evropě. Výskyt T. scripta na našem území nejvíce ovlivňují: lidská činnost, průměrná roční teplota a teplotní charakteristiky chladných období. Trachemys scripta prochází na našem území procesem naturalizace a kritickým bodem by, zejména z hlediska možností inkubace vajec, mohly být teplotní podmínky. Možnosti úspěšné inkubace vajec T. scripta byly měřeny přímo na lokalitách v terénu a porovnány pomocí sumy efektivních teplot (SET) nad spodním prahem vývoje (SPV). V sezóně 2012-2013 bylo SET na území ČR dosaženo na lokalitách v Praze. Místa, kde bylo v průběhu měření dosaženo sumy efektivních teplot na území ČR, jsou urbánními biotopy. T. scripta lze v České republice považovat za přechodně zavlečený kryptogenní nepůvodní druh (casual)...
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