Made available in DSpace on 2015-04-17T14:55:26Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 8341348 bytes, checksum: 3c793b10a08a57a4fe65df46346e7385 (MD5) Previous issue date: 2013-03-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The first classifications for the annelids were presented within a peculiar group of worms grouped within Class Vermes. The group was initially divided into Errant Annelides, Tubicolous or Sedentary Annelides, Terricolous Annelids, and Freshwater Annelids. These classifications did not reflect common ancestry. With the advent of phylogenetic systematics, many proposals were made for other organisms, attempting to reflect true relationships. The first proposals for annelids and polychaetes appeared in the 90s, based on morphology, and attempted to confirm the monophyly of these two groups. In these analyses, the Pogonophora were reduced to a family of Polychaeta, the Siboglinidae. These results remained incongruent when compared to results obtained later from molecular data. Another phylogenetic proposal presented the Pogonophora as being close to the sedentary polychaetes, closely related to Owenia. In this proposal, the clade Metameria was established to group the annelids, Enterocoela and Deuterostomia. Pogonophora as a family of Polychaeta disregards the evolutionary relationships that this taxon shares with the deuterostomes. In the present work, polychaetes with tori were selected as the ingroups of the analysis, together with Pogonophora, and including Phoronida and Pterobranchia, in order to establish genealogical relationships among these taxa. For parsimony analyses molecular data from 18S rRNA, morphological data coded as binary (a/p), multistate, and combined data (multistate molecular and morphological data) were used. Several slightly different topologies appeared in our results on morphology and molecules. On the other hand, the combined data was similar to the topology obtained from multistate morphology. From these analyses, we hypothesize that sedentary polychaetes with tori (including Pogonophora) are strictly related to Phoronida and Deuterostomia, their tagmatization being considered a particularly important synapomorphy. Finally, we emphasize the paraphyletic nature of Protostomia, Spiralia, Trochozoa and Lophotrochozoa, which are contrasted to the monophyletic Metameria. / As primeiras classificações para os anelídeos foram representadas para um grupo peculiar de vermes que formavam as primeiras famílias de poliquetas, agrupadas dentro da Classe Vermes. O grupo foi dividido inicialmente em Annélides Errantes, Annélides tubicoles ou Sédentaires, Annélides Terricoles e Annélides souceuses. Essas classificações não refletiam ancestralidade comum. Com o surgimento da sistemática filogenética, muitas propostas foram apresentadas para vários outros grupos de organismos, buscando refletir as relações de parentescos. A partir da década de 90 surgiram os primeiros trabalhos de filogenia com dados morfológicos para os anelídeos e poliquetas, com objetivo de confirmar a monofila dos dois grupos. Nestas análises, Pogonophora foi reduzido a uma família de Polychaeta, os Siboglinidae. Os resultados permaneceram incongruentes quando comparados os dados morfológicos com os dados moleculares, que surgiram posteriormente. Outras propostas filogenéticas apresentaram os Pogonophora como grupo próximo aos poliquetas sedentários, relacionados com os Owenia. Nessa proposta, foi estabelecido o clado Metameria para agrupar anelídeos, Enterocoela e Deuterostomia. Pogonophora como uma família de Polychaeta quebra a relação de paradigma evolutivo que este táxon compartilha com os Deuterostômios. Neste trabalho, se usou como grupo interno poliquetas com tori, Pogonophora, Phoronida e Pterobranchia, a fim de estabelecer relações genealógicas entre eles. Desta forma, se usou para análise de parcimônia dados moleculares 18S rRNA, dados morfológicos codificados como binário e multiestados, e dados combinados (moleculares e morfológicos multiestados). Os resultados mostraram várias hipóteses que se diferenciaram um pouco nas topologias, quando foram comparados os cladogramas de caracteres moleculares com os cladogramas de caracteres morfológicos. Embora, a topologia de caracteres combinadas se mostrou igual à topologia de caracteres morfológicos multiestados. Dessa maneira, hipotetiza-se a partir das análises aqui obtidas, que os poliquetas sedentários portadores de tori (incluindo Pogonophora) estão estritamente relacionados aos Phoronida e Deuterostomia, principalmente quando se ressalta o processo de tagmatização. Finalmente, enaltece-se a parafilia de Protostomia, Spiralia, Trochozoa e Lophotrochozoa, ressaltando o monofiletismo de Metameria.

Radim Žídek "Wnt/β-catenin signalling in the development of the marine annelid Platynereis dumerilii" (dissertation) Abstract: Wnt/β-catenin signalling is absolutely crucial for the early embryonic development of metazoan animals from the establishment of body axes, through the specification of germ layers and tissues to the development of organ systems. I used pharmacological manipulations of the Wnt/β-catenin pathway activity in the planktonic larvae of the marine polychaete annelid Platynereis dumerilii, the representative of the clade Spiralia, to investigate the role of Wnt/β- catenin signalling in the development and evolution of three hallmarks of Bilateria: the central nervous system, the body segmentation and the digestive tube. Wnt proteins are produced in all three aforementioned systems in Platynereis where they trigger the Wnt/β-catenin pathway in neighbouring cells. I describe here, for the first time in Platynereis, a homologue of the endpoint transcription factor of the entire pathway, Pdu-Tcf, which is subjected to an alternative splicing and along with a Wnt target gene Pdu-Axin is expressed in tissues with the active Wnt signalling - in the brain ganglia, in the neuroectoderm along the ventral midline, in segments, in the posterior growth zone and in the gut. Pharmacological manipulations...

The evolutionary origin and the phylogeny of higher metazoan taxa is still under debate although considerable progress has been made in the past 20 years. Metazoa represents a monophyletic group of highly diverse animals including Bilateria, Cnidaria, Porifera, Ctenophores, and Placozoa. Bilateria comprises the majority of metazoans and consists of three major clades: Deuterostomia, Spiralia (= Lophotrochozoa sensu lato), and Ecdysozoa, whereas the sister group taxa Spiralia and Ecdyzozoa form the monophyletic clade Protostomia. Molecular data have profoundly changed the view of the bilaterian tree of life. One of the main questions concerning bilaterian phylogeny is the on-going debate about the evolution of complexity in Bilateria. It was assumed that the last common ancestor of Deuterostomia, Ecdysozoa and Spiralia had a segmented and coelomate body organization resembling that of an annelid. On the contrary, the traditional view is the evolution of Bilateria from a simple body organization towards more complex forms, assuming that the last common ancestor of Bilateria resembles a platyhelminth-like animal without coelomic cavities and segmentation. To resolve this question, it is necessary to unravel the phylogenetic relationships within Bilateria. By using mitogenomic and phylogenomic data, this thesis had a major contribution to clarify phylogenetic relationships within problematic metazoan taxa: (1) the phylogeny of Deuterostomia, (2) the questionable monophyly of Platyzoa, and first assumptions concerning the phylogeny of Gnathostomulida, Gastrotricha and Polycladida, (3) phylogenetic relationships within annelid taxa, especially Terebelliformia, Diurodrilidae, and Syllidae, with new insights into the evolution of mitochondrial gene order, and (4) new insights into the evolution of annelids, especially the interstitial ones, as well as the colonization of the interstitial realm.