Multi-component signalling in turtles and squamate reptiles

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...

Bitcoin and analysis of its price development

Práce Bitcoin a analýza vývoje jeho ceny se zabývá problematikou kryptoměn, a především potom Bitcoinu. Ten v současné době zažívá strmý nárůst ceny a začíná se o něj zajímat široká veřejnost. Jak Bitcoin vlastně funguje? Proč se musí těžit? Co to jsou altcoiny? Na tyto otázky se snaží odpovědět první kapitola, která by měla obstarat určitý teoretický základ následujícím částím. Druhá kapitola se zaměřuje na cenový vývoj Bitcoinu do prosince roku 2020 a popisuje situace, které mohly stát za poklesy a růsty této kryptoměny. Poslední kapitola analyzuje základní fundamenty ekonomiky, které cenu Bitcoinu ovlivňují, snaží se určit v jakém životním cyklu se Bitcoin zrovna nachází a jak vypadá jeho regulace ze strany některých států.The main topic of bachelor´s work Bitcoin and analysis of its price are cryptocurrencies, especially Bitcoin. Bitcoin´s price has been rising significantly for last months, which increased popularity of this cryptocurrency. How does Bitcoin actually work? Why does it have to be mined? What are altcoins? The first chapter should give you answer for these questions and should obtain theoretical basis for other parts of the work. Second chapter is focused on Bitcoin´s price development until December 2020 a describe situations, that may have been behind the declines and increases in this cryptocurrency. The last chapter analyse the basic fundamentals of the economy that affect the price of Bitcoin, tries to determine in which life cycle Bitcoin is currently located and what its regulation by some states looks like

Data from: Body coloration and mechanisms of colour production in Archelosauria: the case of deirocheline turtles

Animal body coloration is a complex trait resulting from the interplay of multiple mechanisms. While many studies address the functions of animal coloration, the mechanisms of colour production still remain unknown in most taxa. Here we compare reflectance spectra, cellular, ultra- and nano- structure of colour-producing elements, and pigment types in two freshwater turtles with contrasting courtship behaviour, Trachemys scripta and Pseudemys concinna. The two species differ in the distribution of pigment cell-types and in pigment diversity. We found xanthophores, melanocytes, abundant iridophores and dermal collagen fibres in stripes of both species. The yellow chin and forelimb stripes of both P. concinna and T. scripta contain xanthophores and iridophores, but the post-orbital regions of the two species differ in cell-type distribution. The yellow post-orbital region of P. concinna contains both xanthophores and iridophores, while T. scripta has only xanthophores in the yellow-red postorbital/zygomatic regions. Moreover, in both species, the xanthophores colouring the yellow-red skin contain carotenoids, pterins, and riboflavin, but T.scripta has a higher diversity of pigments than P. concinna. Trachemys s. elegans is sexually dichromatic. Differences in the distribution of pigment cell types across body regions in the two species may be related to visual signalling but do not match predictions based on courtship position. Our results demonstrate that archelosaurs share some colour production mechanisms with amphibians and lepidosaurs (i.e., vertical layering/stacking of different pigment cell types and interplay of carotenoids and pterins), but also employ novel mechanisms (i.e., nano-organization of dermal collagen) shared with mammals

Turtle_coloration_datafiles

The archive contain all datafiles used in analyses in the manuscript: Body coloration and mechanisms of colour production in Archelosauria: The case of deirocheline turtles. Specificaly there are: reflectance spectra of all individual turtles, summary variables derived from reflectance spectra of all individuals, R script of multivariate analyses of summary variables, electromicrographs of reflecting platelets of turtles' iridophores, measurements of reflecting platelets of iridophores, electromicrographs of collagen fibres used in Fourier analyses, output files resulting from Fourier analyses of collagen fibres, and description of changes in Fourier tool script provided by Dr. Prum (https://prumlab.yale.edu/research/fourier-tool-analysis-coherent-scattering-biological-nanostructures) that were necessary to secure compatibility of current versions of MATLAB

PodMur1.0

PodMur1.

Data from: Regulatory changes in pterin and carotenoid genes underlie balanced color polymorphisms in the wall lizard

Reptiles use pterin and carotenoid pigments to produce yellow, orange, and red colors. These conspicuous colors serve a diversity of signaling functions, but their molecular basis remains unresolved. Here, we show that the genomes of sympatric color morphs of the European common wall lizard (Podarcis muralis), which differ in orange and yellow pigmentation and in their ecology and behavior, are virtually undifferentiated. Genetic differences are restricted to two small regulatory regions, near genes associated with pterin (SPR) and carotenoid metabolism (BCO2), demonstrating that a core gene in the housekeeping pathway of pterin biosynthesis has been co-opted for bright coloration in reptiles and indicating that these loci exert pleiotropic effects on other aspects of physiology. Pigmentation differences are explained by extremely divergent alleles and haplotype analysis revealed abundant trans-specific allele sharing with other lacertids exhibiting color polymorphisms. The evolution of these conspicuous color ornaments is the result of ancient genetic variation and cross-species hybridization

Data from: Regulatory changes in pterin and carotenoid genes underlie balanced color polymorphisms in the wall lizard

Reptiles use pterin and carotenoid pigments to produce yellow, orange, and red colors. These conspicuous colors serve a diversity of signaling functions, but their molecular basis remains unresolved. Here, we show that the genomes of sympatric color morphs of the European common wall lizard (Podarcis muralis), which differ in orange and yellow pigmentation and in their ecology and behavior, are virtually undifferentiated. Genetic differences are restricted to two small regulatory regions, near genes associated with pterin (SPR) and carotenoid metabolism (BCO2), demonstrating that a core gene in the housekeeping pathway of pterin biosynthesis has been co-opted for bright coloration in reptiles and indicating that these loci exert pleiotropic effects on other aspects of physiology. Pigmentation differences are explained by extremely divergent alleles and haplotype analysis revealed abundant trans-specific allele sharing with other lacertids exhibiting color polymorphisms. The evolution of these conspicuous color ornaments is the result of ancient genetic variation and cross-species hybridization

Amplicon alignments

Amplicon alignment