Neurulation in vertebrates: comparative and evolutionary points of view

Vznik neurální trubice procesem neurulace je zásadní událost, která probíhá v embryogenezi každého obratlovce. Pro správné pochopení neurulace je vhodné zohlednit znalosti embryogeneze blízce příbuzných skupin obratlovců, jakými jsou pláštěnci a kopinatci, a také polostrunatci, coby vzdálenější příbuzní v rámci druhoústých. Neurulace probíhá u obratlovců podle obecného vzoru, kdy se neurální destička prohýbá a vnořuje do embrya. V průběhu zanořování se po jejích okrajích zvedají neurální valy, jejichž vrcholky splynou a vytvoří tak neurální trubici. S pouze drobnými odlišnostmi se tento způsob neurulace nachází u bezčelistnatců (Cyclostomata), paryb (Chondrichthyes) a také u svaloploutvých (Sarcopterygii). Nicméně u paprskoploutvých ryb (Actinopterygii), které reprezentují téměř polovinu všech v současnosti žijících organismů, probíhá neurulace poněkud odlišně. Zatímco u bazálních paprskoploutvých ryb, kterými jsou bichiři, jeseteři nebo kostlíni, vzniká neurální trubice spíše podle výše zmíněného schématu, odvozenější kostnaté ryby a také kaprouni vytvářejí svou neurální trubici přes stádium pevného, tzv. neurálního kýlu, v němž se centrální lumen vytváří až druhotně. V této práci jsou zahrnuty kromě informací o procesech neurulace u výše zmíněných, často málo prozkoumaných skupin, také popisy...Neurulation is an essential developmental process leading to the formation of neural tube that occurs during early embryogenesis of all vertebrates. In order to better understand neurulation of our own group, we should take into account also the modes of neurulation that take place in closely related vertebrate groups. This bachelor thesis is intended to summarize our knowledge on neurulation across vertebrates, but also in our sister groups like tunicates, amphioxus, or acorn worms. In vertebrates, neurulation typically proceeds via a common scheme that includes bending of a neural plate towards the dorsal midline, together with elevation of the neural folds. The neural tube is fully established when neural folds are brought into contact and fuse together. With some minor modifications, this scheme is common in the jaw-less fishes (Cyclostomata), cartilaginous fishes (Chondrichthyes) and also in the lobe-finned fishes (Sarcopterygii). However, in the ray-finned fishes (Actinopterygii) that represent nearly half of all recent vertebrate species, the neurulation proceeds rather differently. Whereas in the basal ray-finned fish lineages like in bichirs, sturgeons, or gars, the neural tube forms rather typically, in more derived teleost fishes and also in Amia, neural tube forms via the so-called...Department of ZoologyKatedra zoologiePřírodovědecká fakultaFaculty of Scienc

Comparative and evolutionary analyses of neurulation in non-teleost fishes

Neurulace, neboli vznik neurální trubice, je zásadní událostí embryogeneze každého obratlovce. Tento proces probíhá podle obecného vzoru, kdy se z neurální ploténky v závěru neurulace vytvoří neurální trubice. U většiny skupin obratlovců probíhá neurulace klasicky ohýbáním neurální ploténky za současného vyzdvižení neurálních valů. U kostnatých ryb (Teleostei), které reprezentují korunovou skupinu paprskoploutvých ryb (Actinopterygii), probíhá neurulace značně rozdílně přes pevný neurální kýl. Tři kmenové linie paprskoploutvých ryb - bichiři, jeseteři a kostlíni - tak mohou sloužit jako unikátní modely pro pochopení evoluční změny ve způsobu neurulace u obratlovců. Pro tento účel byla využita podrobná vývojová série bichira senegalského (Polypterus senegalus), jesetera malého (Acipenser ruthenus) a kostlína mexického (Atractosteus tropicus) a byly porovnány jejich morfogenetické procesy neurulace. Z popisu vnější, tkáňové i buněčné morfologie těchto tří druhů byly zdůrazněny vlivy působící v rámci neurální ploténky (apikální konstrikce, konvergentní extenze) a vlivy okolních tkání na neurální ploténku. Pokusila jsem se také diskutovat případné mechanismy evoluční přechodu od svinování neurální destičky k neurulaci skrze neurální kýl, který představuje unikátní evoluční změnu, se kterou se setkáváme...Neurulation, i. e. formation of a neural tube, is a crucial event in embryogenesis of each vertebrate. This developmental process is rather stereotypical, generally comprising a transformation of a neural plate into a neural tube. In the majority of vertebrate groups, neurulation classically occurs by a folding process of bending neural folds, whereas in bony fishes (Teleostei), representing a crown group of ray-finned fishes (Actinopterygii), the neurulation occurs rather differently by a solid neural keel. The three stem groups of ray- finned fishes - bichirs, sturgeons and gars - might thus serve as unique models for understanding of evolutionary changes in the pattern of vertebrate neurulation. For that reason, detailed developmental series of bichir (Polypterus senegalus), sturgeon (Acipenser ruthenus) and gar (Atractosteus tropicus) were used, and their morphogenetic processes of neurulation were compared. I present here description of the outer morphology, and analyses of tissue and cellular changes, with a focus on intrinsic forces within the neural plate like apical constriction and convergent extension, as well as on some extrinsic forces. I also try to discuss possible mechanisms of an evolutionary transition from the bending of the neural plate to the neurulation via the neural keel,...Katedra zoologieDepartment of ZoologyPřírodovědecká fakultaFaculty of Scienc

Migratory patterns and evolutionary plasticity of cranial neural crest cells in ray-finned fishes

The cranial neural crest (CNC) arises within the developing central nervous system, but then migrates away from the neural tube in three consecutive streams termed mandibular, hyoid and branchial, respectively, according to the order along the anteroposterior axis. While the process of neural crest emigration generally follows a conserved anterior to posterior sequence across vertebrates, we find that ray-finned fishes (bichir, sterlet, gar, and pike) exhibit several heterochronies in the timing and order of CNC emergence that influences their subsequent migratory patterns. First, emigration of the cranial neural crest in these fishes occurs prematurely compared to other vertebrates, already initiating during early neurulation and well before neural tube closure. Second, delamination of the hyoid stream occurs prior to the more anterior mandibular stream; this is associated with early morphogenesis of key hyoid structures like external gills (bichir), a large opercular flap (gar) or first forming cartilage (pike). In sterlet, the hyoid and branchial CNC cells form a single hyobranchial sheet, which later segregates in concert with second pharyngeal pouch morphogenesis. Taken together, the results show that despite generally conserved migratory patterns, heterochronic alterations in the timing of emigration and pattern of migration of CNC cells accompanies morphological diversity of ray-finned fishes

Education of Seniors in Civil Society Organizations in the Czech Republic

Organisations of different type and legal status engage in senior education in the Czech Republic. Civil society organisations available online are not the dominant providers of educational courses and activities for seniors in the Czech Republic. Civil society organisations represent 17 % of all providers of educational courses available online. Six civil society organisations engaged in senior education were found in the region Vysočina. Participants of the educational courses consider all activities practised in these courses to be education because they learn new skills there. They appreciate these courses for the education itself, for meaningful free time spending and for the opportunity of active life even in the time of senescence. For nearly the most important point considered by the participants so as the organisators is connecting and broadening of social contacts of the participants and creating of social network. This can be considered for the most distinct manifestation of civil society concerning senior education

Comparative and evolutionary analyses of neurulation in non-teleost fishes

Neurulation, i. e. formation of a neural tube, is a crucial event in embryogenesis of each vertebrate. This developmental process is rather stereotypical, generally comprising a transformation of a neural plate into a neural tube. In the majority of vertebrate groups, neurulation classically occurs by a folding process of bending neural folds, whereas in bony fishes (Teleostei), representing a crown group of ray-finned fishes (Actinopterygii), the neurulation occurs rather differently by a solid neural keel. The three stem groups of ray- finned fishes - bichirs, sturgeons and gars - might thus serve as unique models for understanding of evolutionary changes in the pattern of vertebrate neurulation. For that reason, detailed developmental series of bichir (Polypterus senegalus), sturgeon (Acipenser ruthenus) and gar (Atractosteus tropicus) were used, and their morphogenetic processes of neurulation were compared. I present here description of the outer morphology, and analyses of tissue and cellular changes, with a focus on intrinsic forces within the neural plate like apical constriction and convergent extension, as well as on some extrinsic forces. I also try to discuss possible mechanisms of an evolutionary transition from the bending of the neural plate to the neurulation via the neural keel,..

Intention of author and reader in contemporary theories of interpretation

Tato práce se zaměřuje na intenci autora a intenci čtenáře v současných teoriích interpretace, konkrétně v mimetické teorii interpretace a teorii fikčních světů. Cílem práce je prozkoumat, co je v těchto konkrétních teoriích důležitější pro určení významu díla, tj. vzájemný vztah mezi intencí autora a čtenáře, respektive jejich možnou hierarchii. Výsledné poznatky jsou pak využity v analýze konkrétního díla, kterým je drama R.U.R. od Karla Čapka.ObhájenoThis thesis focuses on the intention of the author and the intention of the reader in contemporary theories of interpretation, specifically in mimetic theory of interpretation and the theory of fictional worlds. The aim of the thesis is to explore what is more important in these particular theories for determining the meaning of the work, i.e. the mutual relationship between the intention of the author and the reader, respectively their possible hierarchy. The resulting knowledge is then used in the analysis of the specific work, which is the drama R.U.R. by Karel Čapek

Integrated multi-omics analysis of chemical signaling in wild rodents

Symbiotic bacteria living with the host in so-called microbiomes have been one of the significant pillars of all aspects of animal evolution, chemical communication included. However, the phenotype, genotype, and microbiome of laboratory animals kept for generations in sterile conditions changed from their wild ancestors leading to profound differences in the laboratory results and the reality of wild animals. To describe the chemical communication in neglected wild rodents, this thesis focuses on the body parts involved in chemical communication (i.e. mouth, vagina, and intestines) and are also inhabited by microbiomes that produce metabolites with the capability of transmitting chemical signals. Using next-generation sequencing and state-of-the-art proteome and metabolome chromatography-mass spectrometry, this thesis covers the analysis of changes in the microbiome, proteome, and metabolome of wild mice in the context of transferring the wild individuals into the captivity, cohousing wild, and laboratory animals and hormonal changes during the estrous cycles. Moreover, this thesis describes and discusses the differences and similarities in the microbiome, proteome, and metabolome on the level of different species (Apodemus sp.), subspecies (Mus musculus domesticus vs. musculus), and environment..

Morality, sociobiology and the selfish gene theory

Bakalářská práci se věnuje oboru sociobiologie a teorii sobeckého genu s ohledem na morálku. Vychází z textu E. O. Wilsona O lidské přirozenosti a z textu R. Dawkinse Sobecký gen. Je zde představen vznik a vývoj oboru sociobiologie, rozebrána podobnost lidí a šimpanzů a následně jsou popsány základní kategorie chování: agresivitu, sexualitu, náboženství a altruismus. Práce se zaměřuje především na sociobiologický výklad těchto kategorií chování. Dále je vysvětlena teorie sobeckého genu. Práce se věnuje vztahu mezi geny a organismy, evolučně stabilním strategiím a projevů sobeckých genů ve formě altruismu. Je zde zmíněna také teorii memů a práce též upozorňuje na kritiku sociobiologie. Cílem práce je představit základní myšlenky sociobiologie a přiblížit její pohled na morálku.ObhájenoThis bachelor thesis deals with the field of sociobiology and the selfish gene theory with regard to morality. It is based on the text On Human Nature by E. O. Wilson and on text The Selfish Gene by R. Dawkins. It presents the origin and development of the field of sociobiology, analyzes the similarity of humans and chimpanzees, and then describes the basic categories of behavior: aggression, sexuality, religion and altruism. The thesis focuses mainly on the sociobiological interpretation of these categories of behavior. Further, the selfish gene theory is explained. The thesis deals with the relationship between genes and organisms, with evolutionarily stable strategies and with manifestations of selfish genes in the form of altruism. The meme theory is also mentioned here and the thesis also draws attention to the critique of sociobiology. The aim of the thesis is to present the basic ideas of sociobiology and to approach its view of morality