O talha-mar Rynchops niger (Rynchopinae) e o trinta-réis-grande Phaetusa simplex (Sterninae), são aves aquáticas migratórias que se reproduzem simultaneamente em muitas praias fluviais da América do Sul. A taxonomia e a sistemática destas subfamílias foram objetos de poucos estudos. Além disso, possuem subespécies cuja delimitação e a caracterização ainda são confusas, além do que, uma revisão rigorosa da validade destes táxons nunca foi feita. E, como consequência dos poucos estudos, existe uma enorme imprecisão sobre a real área de distribuição de cada táxon, não havendo muita informação sobre os locais para onde se movimentam após o período reprodutivo. Assim sendo, este trabalho teve como objetivo caracterizar geneticamente e revisar a taxonomia destas duas espécies polítipas, definindo os seus táxons válidos e distribuição. Para tal, foram utilizados caracteres morfológicos (de plumagem e morfométricos), sequências do gene mitocondrial ND2 e de marcadores associados a sítios de restrição (ddRADseq), a fim de estimar a variação intra e interpopulacional, o fluxo gênico e a estrutura genética; visando também entender o padrão de migração destes táxons na América do Sul e a influência dos rios na taxonomia e na história evolutiva destas aves. De acordo com os resultados conclui-se: P. simplex passa a ser considerado um táxon monotípico, pois não é possível separar as subespécies entre si, nem morfologicamente e nem geneticamente. Apesar das variações genéticas entre as três subespécies de R. niger não serem significativas, estas continuam a ser consideradas como subespécies válidas, pois puderam ser plenamente diagnosticáveis quanto aos caracteres de plumagem e de distribuição. Não existem variações genéticas significativas entre as populações. As populações podem estar passando por um processo de expansão recente ou seleção positiva; ou podem estar se comportando como uma metapopulação. Os grandes rios sul-americanos, juntamente com o ciclo sazonal de precipitação da América do Sul (que altera a dinâmica destes rios), influenciam diretamente na distribuição, e, consequentemente, na evolução das aves aqui analisadas. Neste caso, os rios funcionam como vias de contato (e não como barreiras) entre os indivíduos, contribuindo para o intenso fluxo gênico dos táxons aqui apresentados / The Black Skimmer (Rynchops niger) and the Large-billed Tern (Phaetusa simplex) are migratory waterbirds that breed simultaneously on river beaches throughout South America. Few studies have been conducted on the taxonomy and systematics of these polytypic species and the delimitation and validity of each taxa described has never been studied in detail. As a result, the geographical distribution of both species is poorly understood and there is little information about the whereabouts of their non-breeding grounds. Therefore, the purpose of this study was to characterize genetically and revise the taxonomy and distribution of these two polytypic species. For this it was integrated morphological characters (plumage and morphometrics), mitochondrial sequences (ND2), and single nucleotide polymorphisms (SNPs) inferred from double digestion restriction associated DNA sequencing (ddRADseq) to estimate: 1) intra- and inter-populational variation, 2) gene flow, 3) population genetic structure, 4) migration patterns of these taxa within South America, and 5) assess the influence of rivers on the taxonomy and evolutionary history of these birds. The results lead to the following conclusions: P. simplex should now be considered a monotypic taxon because currently recognized subspecies are neither morphologically nor genetically diagnosable. Although genetic variation between the three subspecies currently recognized in R. niger is not significant, these taxa continue to be considered as valid subspecies because they are fully diagnosable in plumage characters and distributional patterns. There are no significant genetic variation between the populations of both species (R. niger and P. simplex). Populations may be undergoing a process of recent expansion or positive selection or they may be behaving like a metapopulation. Main South American rivers, together with the seasonal precipitation cycles of South America (which changes the dynamics of these rivers), have direct influence on the distribution, and, consequently, on the evolution of these birds. In this case, the rivers function as pathways of contact (and not as barriers) between individuals, contributing to the intense gene flow between these taxa

O gênero Persephona Leach, 1817 é restrito a América e é constituído por dez espécies com ocorrência no Atlântico Ocidental e Pacífico Oriental, estando inserido na subfamília Ebaliinae, a qual não se encontra taxonomicamente bem estabelecida. Ao longo dos anos, este gênero foi alocado em diferentes subfamílias e sua classificação é mal definida. Além disso, existem chaves de identificação que não permitem a correta identificação das espécies dentro do gênero. Estas infomações são indicativos de uma forte necessidade de estudos enfocando Persephona, os quais podem fornecer uma melhor compreensão sobre a história evolutiva do gênero. Neste contexto, o presente estudo pretendeu realizar uma ampla revisão taxonômica do gênero Persephona, incluindo caracteres que possuem grande variabilidade dentro do gênero (número e tamanho dos espinhos, quelípodos, etc), caracteres tradicionalmente utilizados na diagnose das espécies, além de outros selecionados a partir do presente estudo (gonópodos, coloração, etc), além de incluir pela primeira vez para o gênero, análises de dados moleculares. Dois genes mitocondriais, o 16S rRNA e o Citocromo Oxidase I (COI) foram utilizados como marcadores. As análises morfológicas revelaram uma ausência de diferenças entre algumas espécies propostas para o gênero Persephona, as quais foram corroboradas pelas análises moleculares. Desta forma, são propostas modificações a respeito da taxonomia de Persephona: P. finneganae é um sinônimo júnior de P. lichtensteinii. O nome P. crinita é valido apenas para os espécimes de ocorrência no Golfo do México; os espécimes de P. mediterranea com ocorrência no Golfo do México, correspondem a P. aquilonaris e aqueles com ocorrência no Caribe e Atlântico Sul, correspondem a P. mediterranea e além do exposto, Iliacantha hancocki é um sinônimo júnior de P. subovata. / The genus Persephona Leach, 1817 is restricted to America and consists of ten species occurring in the Western Atlantic and Eastern Pacific. It belongs to the subfamily Ebaliinae, which is not taxonomically well established. Over the years, Persephona was placed in different subfamilies and its classification is still poorly defined. Also, existing identification keys do not allow a correct classification of the species within the genus. These informations are indicatives of a strong need of studies focusing on Persephona, which can provide a better understanding concerning its evolutionary history. In this context, the present study intends to undertake a broad taxonomic revision of the genus Persephona, including characters possessing great variability within the genus (number and size of the spines, cheliped, etc.), characters traditionally used in the diagnosis of the species, and others selected from the present study (gonopod, coloration, etc.), including for the first time for the genus, analyses of molecular data. As guides for the molecular analyses, two mitochondrial genes, the 16S rRNA and the Cytochrome Oxidase I (COI) were used as markers. The morphological analyses revealed an absence of differences among some species proposed for the genus Persephona, wich were corroborated by molecular and phylogenetic analysis. In this way, is propose modifications regarding Persephona taxonomy: P. finneganae is a junior synonym of P. lichtensteinii: the name P. crinita is valid only for specimens occurring in the Gulf of Mexico; the specimens of P. mediterranea with occurence in the Gulf of Mexico, correspond to P. aquilonaris and those with occurence in the Caribbean and South Atlantic correspond to P. mediterranea, moreover I. hancocki is a junior synonym of P. subovata.

Einleitung: Die Entdeckung somatischer homoplasmischer Mutationen der mitochondrialen DNA (mtDNA) in Tumoren gab Anlass zu der Frage, ob Mutationen der mtDNA einen Einfluss auf Entstehung und Wachstum von Tumoren haben könnten. Die Neurofibromatose Typ 1 (NF1, von Recklinghausen) ist eine der häufigsten erblichen Tumorerkrankungen mit einer Penetranz von 100%, aber hoher phänotypischer Variabilität. Selbst eineiige Zwillinge können sich erheblich in ihrem Phänotyp unterscheiden. Durch die ungleiche Verteilung der Mitochondriengenome auf die Embryonen könnten heteroplasmische mtDNA-Polymorphismen den Phänotyp der Neurofibromatose Typ 1 unterschiedlich beeinflussen. Ziel dieser Arbeit war es herauszufinden, ob es interindividuelle Unterschiede in der mtDNA-Sequenz monozygoter Zwillinge gibt, die an Neurofibromatose Typ 1 erkrankt sind, sich jedoch im Phänotyp unterscheiden. Des Weiteren habe ich nach intraindividuellen Unterschieden der mtDNA-Sequenz zwischen Blut und Tumorgewebe gesucht. Die Frage war, ob es somatische mtDNA-Mutationen gibt, die einen Einfluss auf das Entstehen der Tumore haben könnten. Innerhalb der mtDNA gibt es hypervariable Regionen (HVR), von denen der oft in heteroplamischer Form vorkommende D310-Trakt im D-loop als Marker für klonales Wachstum in Tumoren empfohlen wurde. Ich habe versucht, durch Analyse des D-loops der mtDNA aus Neurofibromen klonales Wachstum nachzuweisen. Methoden: Ich habe die mitochondriale DNA vier monozygoter Zwillingspaare untersucht. Die DNA wurde sowohl aus Blutleukozyten als auch aus Neurofibromen extrahiert. Ich habe zunächst mit mtDNA-spezifischen Primern eine Long-range PCR durchgeführt. Mit dem Long-range PCR-Produkt als Matrize habe ich in 17 verschachtelten PCR Reaktionen Fragmente generiert und diese sequenziert. Den relativen Anteil heteroplasmischer Längenvarianten des D310-Traktes ermittelte ich mittels Genotypisierung. Ergebnisse: Beim Vergleich der mtDNA-Sequenzen mit der mtDNA Standardsequenz (Genbank, NC_001807) habe ich insgesamt 88 Abweichungen gefunden. Die meisten waren in der Datenbank Mitomap verzeichnet. Es fanden sich keine interindividuellen Unterschiede innerhalb der einzelnen Paare. Beim Vergleich der mtDNA-Sequenzen aus Blut- mit denen aus Tumorzellen eines Zwillingspaares fand ich keinen intraindividuellen Unterschied. Der D310-Trakt innerhalb der HVR2 kam bei allen Zwillingspaaren in heteroplasmischer Form vor. Bei den Zwillingen A1 und A2 sowie deren Mutter MA konnte ich annähernd die gleiche Verteilung der Löngenvarianten in Blutzellen sowie in Neurofibromen von A1 und A2 zeigen. Schlussfolgerungen: Ich konnte keinen Hinweis dafür finden, dass Veränderungen in der mtDNA die phänotypische Ausprägung der NF1 beeinflussen. In Neurofibromen konnte ich durch Untersuchung des D310-Traktes keinen Hinweis auf klonales Wachstum finden. / Introduction: The discovery of homoplasmic somatic mutations of the mitochondrial DNA (mtDNA) led to the question whether mutations of mtDNA could influence tumor development and growth. Neurofibromatosis Type 1 (NF1) is one of the most common inherited disorders. Penetrance of the disease is 100%, but phenotypic variability is high, even amongst identical twins. I wanted to test the hypothesis, whether the unequal distribution of heteroplasmic mtDNA variants between the embryos might influence NF1 phenotype. The aim of this study was to look for interindividual differences of the mtDNA sequence between identical twins. In order to detect somatic mutation that could possibly influence tumor development I searched for intraindividual differences between blood- and tumor-mtDNA. The hypervariable D310-tract within the D-loop is heteroplasmic in most individuals, but shows a tendency towards homoplasmy in tumors. Therefore, it has been proposed as marker for clonal tumor growth. I tried to identify clonal growth in cutaneous neurofibromas by examination of the D310-tract. Methods: I examined the mtDNA from four pairs of identical twins. MtDNA was extracted from blood-leucocytes as well as from neurofibromas. With DNA-specific primers I first performed a long-range PCR. The product was then reamplified as 17 nested PCR fragments and sequenced afterwards. The relative amount of heteroplasmic D310-tract length variants was analyzed by genotyping. Results: Taken together, I identified 88 deviations from the mtDNA standard sequence (Genbank NC_001807). Most of these variants were already known as polymorphisms in the database MITOMAP. I could neither find any interindividual differences between the individuals of a twin pair nor intraindividual differences between blood- and tumor-mtDNA. The D310-tract was heteroplasmic in all twin pairs. Twins A1 and A2 as well as their mother showed almost the same distribution of length variants in blood and tumor. Conclusion: I could not show that mtDNA polymorphisms play a role in phenotypic variability of NF1. Examination of the D310 tract in cutaneous neurofibromas did not show signs of clonal growth.

L’instabilité d’ADN mitochondrial (ADNmt) peut être quantitative avec la déplétion de l’ADNmt ou qualitative avec des délétions de l’ADNmt. Ces anomalies sont une des causes les plus commmunes des maladies mitochondriales. Un des gènes qui contrôle la stabilité et le maintien de l’ADNmt est POLG. Ce gène code pour la polymerase gamma mitochondriale. Chez l’homme, les mutations dans le gène POLG sont liées aux maladies mitochondriales telle que; l’insuffisance hépatique, le syndrome d’Alpers, le PEO ou Progressive External Ophtalmoplegia, la neuropathie sensorielle et l’ataxie. Des mutations dans le gène POLG sont aussi associées au syndrome de Parkinson. Aujourd’hui, il n’existe aucune thérapie pour ces maladies. Compte tenu de la conservation évolutive de la fonction mitochondriale de la levure à l’homme, nous avons utilisé deux organismes modèles, Saccharomyces cerevisiae et Caenorhabditis elegans, pour identifier des molecules chimiques capables de compenser l’instabilité de l’ADNmt liée à des mutations du gène POLG dans des fibroblastes d’un patient. Nous avons trouvé trois molécules candidates potentielles: MRS2, MRS3 et MRS4, à partir d’un criblage primaire chez la levure, en utilisant une chimiothèque d’environ 2000 molécules chimiques. MRS3 est la molécule candidate la plus efficace pour la stabilization d’ADNmt chez des mutants POLG de la levure, du champignon filamenteux, du nématode et sur des fibroblastes de patients. MRS3, ou clofilium tosylate (CLO), est un agent antiarrhytmique, médicament pour soigner les troubles du rythme cardiaque. Dans cette étude, nous avons aussi montré que deux autres antiarrhythmiques appartenant à la même classe que CLO avaient un effet positive chez un mutant POLG de C. elegans. En utilisant une approche de chemogénomique chez la levure, nous avons identifié Fis1, un acteur de la fission mitochondriale qui pourrait être impliqué dans la mode d’action de CLO. Fis1 est requise pour la viabilité cellulaire en concentration légèrement toxique de CLO et nécesaire pour la stabilization de l’ADNmt par CLO. L’ensemble de ces résultats ont montré que CLO pourrait être la première molécule chimique qui stimule la réplication de l’ADNmt et qui pourrait être développée pour le traitement des maladies liées à des mutations dans le gène POLG. Ces résultats ont aussi permis de mettre en évidence une nouvelle connexion entre replication de l’ADNmt et la fission mitochondriale. / The instability of mitochondrial DNA (mtDNA) in form of mtDNA depletion (quantitative instability) or large deletion (qualitative instability) is one of the most common cause of mitochondrial diseases.. One of the genes responsible for human mtDNA stability, POLG, is exploited in this study. POLG encodes the human mitochondrial polymerase gamma. In human, POLG mutations are a major cause of mitochondrial disorders including hepatic insufficiency; Alpers syndrome, progressive external ophthalmoplegia, sensory neuropathy and ataxia. They are also associated with Parkinsonism. Currently, there is no effective and disease-specific therapy for these diseases. Based on the conservation of mitochondrial function from yeast to human, we used Saccharomyces cerevisiae and Caenorhabditis elegans as first pass filters to identify chemical compounds that suppresses mtDNA instability in cultured fibroblasts of a POLG-deficient patient. We found three potential candidates, MRS2, MRS3 and MRS4, from a chemical screening of nearly 2000 compounds in yeast. MRS3 is the most efficacious in stabilizing mtDNA in yeast, filamentous fungi, worm and patient fibroblasts. This unsuspected compound, clofilium tosylate (CLO), belongs to a class of antiarrhythmic agents for cardiovascular disease. Two other antiarrhythmic agents (FDA-approved) sharing common pharmacological properties and chemical structure with CLO also show potential benefit for POLG deficiency in C. elegans. Using a chemogenomic approach in yeast, we also discovered that a mitochondrial fission actor Fis1 is implicated in the mechanism of action of CLO. Fis1 is important for cellular viability in a slightly toxic concentration of CLO and is required for the mtDNA stabilizing potency of CLO. Our findings provide evidence of the first mtDNA-stabilizing compound that may be an effective pharmacological alternative for the treatment of POLG-related diseases and uncover a new connection between the mitochondrial fission process and mtDNA replication. / Ketidakstabilan DNA mitokondria (mtDNA) dalam bentuk pengurangan kopi mtDNA di dalam sel (ketidakstabilan kuantitatif), atau pun dalam bentuk delesi pada sekuens mtDNA (ketidakstabilan kualitatif) merupakan salah satu penyebab penyakit mitokondria. Salah satu gen yang bertanggung jawab dalam menjamin kestabilan mtDNA adalah POLG. Gen POLG mengkode protein polimerase gamma pada manusia, yang mereplikasi dan mereparasi mtDNA di dalam mitokondria. Mutasi pada gen POLG dapat menyebabkan penyakit kelainan mitokondria pada manusia, seperti gagal ginjal, sindrom Alpers, Progressive External Ophtalmoplegia, neuropati sensorial, ataxia dan bisa dikaitkan dalam beberapa gejala Parkinsonisme. Saat ini, belum ada terapi obat yang dapat mengatasi penyakit – penyakit tersebut. Berdasarkan kesamaan evolutif dari ragi hingga manusia, pada studi ini kami menggunakan Saccharomyces cerevisiae dan Caenorhabditis elegans untuk mengidentifikasi molekul obat yang berpotensi mengatasi ketidakstabilan mtDNA dari fibroblas pasien manusia yang memiliki mutasi gen POLG. Kami mengidentifikasi tiga kandidat potensial, yakni MRS2, MRS3 dan MRS4 dari penapisan kurang lebih 2000 molekul obat dengan menggunakan ragi. MRS3 adalah kandidat yang paling berkhasiat dan mampu mengatasi ketidakstabilan mtDNA pada ragi, Podospora, cacing dan fibroblas manusia. MRS3 adalah alias bagi clofilium tosylate (CLO), sebuah molekul antiaritmia untuk penyakit kardiovaskuler. Pada studi ini, kami juga menguji aktifitas dua molekul antiaritmia lain yang tergabung dalam kelas yang sama dengan CLO, dan menemukan bahwa kedua molekul ini juga berpotensi mengatasi defisit POLG pada cacing C. elegans. Dengan menggunakan metode kemogenomik pada ragi, kami juga mengidentifikasi sebuah aktor prosesus pembelahan mitokondria, Fis1, yang berpotensi terlibat dalam mekanisme seluler CLO. Fis1 dibutuhkan untuk: (1) kelangsungan hidup ragi pada konsentrasi toksik CLO dan (2) efek CLO dalam menstabilkan mtDNA pada ragi. Keseluruhan studi ini membuktikan potensi CLO sebagai molekul penstabil mtDNA yang pertama, yang dapat dikembangkan sebagai salah satu alternatif terapi obat untuk penyakit – penyakit mitokondria terkait mutasi POLG. Melalui studi ini, juga diungkap adanya hubungan antara kestabilan mtDNA dan prosesus pembelahan mitokondria.

Orientador: Rogério Caetano da Costa / Resumo: O camarão-rosa Farfantepenaeus paulensis é um dos mais importantes recursos pesqueiros da costa sul-sudeste do Brasil. Os fundos de pesca da espécie incluem dois estoques reprodutivos principais, localizados nas costas dos estados de Santa Catarina e São Paulo. A espécie apresenta ciclo de vida do tipo II, com uma fase reprodutiva no ambiente marinho e recrutamento juvenil em áreas estuarinas e baías. O conhecimento sobre o fluxo gênico entre estoques é a base de todo o ordenamento pesqueiro, uma vez que unidades genéticas podem apresentar características particulares e, normalmente, necessitam de estratégias específicas de manejo. Porém, há poucas informações que podem servir de subsídio para verificar se os diferentes estoques pesqueiros de F. paulensis também representam estoques genéticos distintos. O crescimento desordenado da frota industrial, o incremento da pesca artesanal nas áreas de criadouro, somado à pequena eficácia da legislação pesqueira, associados à ineficiência da fiscalização, levaram a um cenário de colapso da pescaria do camarão rosa no fim dos anos 90. Um melhor entendimento da estruturação genética das populações de F. paulensis é necessário, não somente pelo seu alto valor comercial e ecológico, mas também para permitir a implementação de medidas de manejo mais efetivas. Assim, o presente trabalho buscou avaliar a estruturação genética das populações do camarão rosa F. paulensis ao longo de sua distribuição no Atlântico Sul Ocidental, utilizando como ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The pink shrimp Farfantepenaeus paulensis is one of the most important fishing resources on the south-southeast coast of Brazil. The fishing zone of the species includes two main reproductive stocks, located on the coasts of Santa Catarina and São Paulo states. The species exhibits the type II life cycle, with an offshore reproductive stage and a juvenile recruitment in bays and estuarine areas. Knowledge on the amount of gene flow between stocks is the basis of all fisheries management, since genetic units may have particular characteristics and usually require specific management strategies. However, there is little information to verify whether F. paulensis's different fish stocks also represent different genetic stocks. The unrestricted growth of the industrial fleet, the increase in artisanal fishing in breeding areas, coupled with the low effectiveness of fisheries legislation and the inefficiency of inspection, led to a collapse of the pink shrimp fishery in the late 1990s. A better understanding of the genetic structuring of the populations of F. paulensis is necessary, not only for its high commercial and ecological value, but also to allow the implementation of more effective management measures. Thus, the present work aimed to assess the genetic structuring of the populations of the pink shrimp F. paulensis throughout its distribution in the Western South Atlantic, using as molecular marker the Control Region (D-loop) of the mitochondrial DNA (Chapter 1). In additi... (Complete abstract click electronic access below) / Doutor

Made available in DSpace on 2016-06-02T19:29:23Z (GMT). No. of bitstreams: 1 3030.pdf: 2014938 bytes, checksum: b6d8f7597811d1909e335b6facc588b7 (MD5) Previous issue date: 2010-03-26 / Universidade Federal de Minas Gerais / The catfishes of the Pseudoplatystoma genus are carnivore pimelodids, migratory and important for fisheries in all major river basins from South America. Only three species were recognized for the genus (P. corruscans, P. fasciatum and P. tigrinum), but a new revision raised to eight the number of species (P. fasciatum, P. punctifer, P. orinocoense, P. magdaleniatum, P. reticulatum, P. tigrinum, P. metaense and P. corruscans). Recently, Pseudoplatystoma was the subject of a molecular phylogeny study based on mitochondrial markers, where monophyletic clades where found for P. tigrinum, P. corruscans, P. reticulatum+P. punctifer+P. fasciatum and P. magdaleniatum. Despite these advances on the knowledge of the evolutionary history and systematics of the group, there are still questions to be answered. Thus, this study aimed a molecular phylogenetic analysis on Pseudoplatystoma to try to answer pendant questions about the systematics and taxonomy of the group, and propose a scenario for its diversification history in the geographic area of South America. In order to do this, we employed the mitochondrial Cytochrome b gene and introns from Rag1 and S7 genes, whose phylogenies were estimated by Maximum Likelihood using TREEFINDER software. Nodes were dated on BEAST software. It was shown that some Pseudoplatystoma species, resulting from the last revision of the genus, do not correspond to monophyletic groups or they were not significantly supported clades in all trees. The only monophyletic species in all markers were P. magdaleniatum and P. corruscans. Pseudoplatystoma orinocoense was a monophyletic lineage only on Cytochrome b. In light of these results, it is suggested that the old terminology P. fasciatum to be revalidated for the taxa here defined as P. fasciatum clade: P. punctifer (Amazon, Maranhão, Tocantins-Araguaia), P. reticulatum (Paraná-Paraguay) and P. fasciatum (Guyanas). Under the same rationale, P. tigrinum should be revalidated for Orinoco, given the paraphyletism of P. metaense. However, some cases of nonmonophyletic species in one or more markers may be due to incomplete lineage sorting, although this possibility needs to be investigated using other markers. The history of diversification of Pseudoplatystoma was the result of millions of years of evolution and and it was strongly influenced by the evolution of the South America geographical matrix. The biogeographic study allowed us to identify and date the important diversification events for the genus and relate them to the historical geomorphological and/or climate changes reported for South America, which would be the primary diversification causes for other freshwater fishes from the continent. / Os bagres do gênero Pseudoplatystoma são pimelodídeos carnívoros, migradores e de importância pesqueira em todas as grandes bacias hidrográficas da América do Sul. Apenas três espécies eram reconhecidas para o gênero (P. corruscans, P. fasciatum e P. tigrinum), mas uma nova revisão elevou para oito o número de espécies (P. fasciatum, P. punctifer, P. orinocoense, P. magdaleniatum, P. reticulatum, P. tigrinum, P. metaense e P. corruscans). Recentemente, Pseudoplatystoma foi alvo de um de estudo de filogenia molecular com marcadores mitocondriais, onde foram encontrados clados monofiléticos para P. tigrinum, P. corruscans, P. reticulatum+P. punctifer+P. fasciatum e P. magdaleniatum. Apesar desses avanços no conhecimento da história evolutiva e da sistemática do grupo, ainda restam questões a serem respondidas. Dessa forma, o presente estudo objetivou uma análise filogenética molecular em Pseudoplatystoma para tentar responder questões pendentes sobre a sistemática e taxonomia do grupo, bem como propor um cenário para sua história de diversificação no espaço geográfico da América do Sul. Para isso, foram empregados o gene mitocondrial do Citocromo b e íntrons dos genes Rag1 e S7, cujas filogenias foram estimadas por Máxima Verossimilhança no programa TREEFINDER. Os nós das filogenias foram datados no programa BEAST. Foi demonstrado que algumas espécies de Pseudoplatystoma, resultantes da última revisão do gênero, não correspondem a grupos monofiléticos ou não tiveram clados significativamente sustentados em todas as árvores. As únicas espécies monofiléticas em todos os marcadores foram P. magdaleniatum e P. corruscans. Pseudoplatystoma orinocoense só foi uma linhagem monofilética no Citocromo b. À luz desses resultados, sugere-se que a antiga terminologia P. fasciatum seja revalidada para os táxons do clado aqui definido como clado P. fasciatum: P. punctifer (Amazonas, Maranhão, Tocantins-Araguaia), P. reticulatum (Paraná-Paraguai) e P. fasciatum (Guianas). Sob a mesma racionalidade, P. tigrinum deveria ser revalidado para o Orinoco, dado o parafiletismo de P. metaense. Entretanto, alguns dos casos de espécies não-monofiléticas em um ou mais marcadores podem ser devidos à separação incompleta de linhagens, embora essa possibilidade necessite ser investigada com o uso de outros marcadores. A história da diversificação de Pseudoplatystoma foi resultado de milhões de anos de evolução e fortemente influenciada pela evolução da matriz geográfica Sul-Americana. O estudo biogeográfico nos permitiu identificar e datar os eventos de diversificação importantes para o gênero e relacioná-los às mudanças geomorfológicas e/ou climáticas históricas conhecidas para a América dos Sul, que seriam as causas primárias de diversificação de outros peixes de água doce do continente.

O gênero Persephona Leach, 1817 é restrito a América e é constituído por dez espécies com ocorrência no Atlântico Ocidental e Pacífico Oriental, estando inserido na subfamília Ebaliinae, a qual não se encontra taxonomicamente bem estabelecida. Ao longo dos anos, este gênero foi alocado em diferentes subfamílias e sua classificação é mal definida. Além disso, existem chaves de identificação que não permitem a correta identificação das espécies dentro do gênero. Estas infomações são indicativos de uma forte necessidade de estudos enfocando Persephona, os quais podem fornecer uma melhor compreensão sobre a história evolutiva do gênero. Neste contexto, o presente estudo pretendeu realizar uma ampla revisão taxonômica do gênero Persephona, incluindo caracteres que possuem grande variabilidade dentro do gênero (número e tamanho dos espinhos, quelípodos, etc), caracteres tradicionalmente utilizados na diagnose das espécies, além de outros selecionados a partir do presente estudo (gonópodos, coloração, etc), além de incluir pela primeira vez para o gênero, análises de dados moleculares. Dois genes mitocondriais, o 16S rRNA e o Citocromo Oxidase I (COI) foram utilizados como marcadores. As análises morfológicas revelaram uma ausência de diferenças entre algumas espécies propostas para o gênero Persephona, as quais foram corroboradas pelas análises moleculares. Desta forma, são propostas modificações a respeito da taxonomia de Persephona: P. finneganae é um sinônimo júnior de P. lichtensteinii. O nome P. crinita é valido apenas para os espécimes de ocorrência no Golfo do México; os espécimes de P. mediterranea com ocorrência no Golfo do México, correspondem a P. aquilonaris e aqueles com ocorrência no Caribe e Atlântico Sul, correspondem a P. mediterranea e além do exposto, Iliacantha hancocki é um sinônimo júnior de P. subovata. / The genus Persephona Leach, 1817 is restricted to America and consists of ten species occurring in the Western Atlantic and Eastern Pacific. It belongs to the subfamily Ebaliinae, which is not taxonomically well established. Over the years, Persephona was placed in different subfamilies and its classification is still poorly defined. Also, existing identification keys do not allow a correct classification of the species within the genus. These informations are indicatives of a strong need of studies focusing on Persephona, which can provide a better understanding concerning its evolutionary history. In this context, the present study intends to undertake a broad taxonomic revision of the genus Persephona, including characters possessing great variability within the genus (number and size of the spines, cheliped, etc.), characters traditionally used in the diagnosis of the species, and others selected from the present study (gonopod, coloration, etc.), including for the first time for the genus, analyses of molecular data. As guides for the molecular analyses, two mitochondrial genes, the 16S rRNA and the Cytochrome Oxidase I (COI) were used as markers. The morphological analyses revealed an absence of differences among some species proposed for the genus Persephona, wich were corroborated by molecular and phylogenetic analysis. In this way, is propose modifications regarding Persephona taxonomy: P. finneganae is a junior synonym of P. lichtensteinii: the name P. crinita is valid only for specimens occurring in the Gulf of Mexico; the specimens of P. mediterranea with occurence in the Gulf of Mexico, correspond to P. aquilonaris and those with occurence in the Caribbean and South Atlantic correspond to P. mediterranea, moreover I. hancocki is a junior synonym of P. subovata.

Les mitochondries, organelles intracellulaires des eucaryotes, fournissent par les oxydations phosphorylantes l'essentiel de l'énergie nécessaire aux différents travaux cellulaires sous la forme d'ATP grâce à un couplage entre la chaîne respiratoire et l’ATPsynthase. Ces réactions du métabolisme énergétique sont assurées par des complexes enzymatiques constitués de sous-unités codées à la fois par l'ADN nucléaire et par l'ADN mitochondrial. Il a été montré que des défauts dans l'activité de ces complexes pouvaient être responsables de l’apparition de pathologies regroupées sous le nom de cytopathies d’origine mitochondriale. Un des problèmes fondamentaux qui se pose lors de l’étude des mécanismes conduisant aux pathologies mitochondriales est de comprendre l’influence de l’ADN mitochondrial sur le métabolisme de la mitochondrie. En effet, la mitochondrie possède son propre ADN, et les mutations de cet ADN sont classées selon leur impact sur le métabolisme mitochondrial : des mutations pathogènes, qui ont des répercussions négatives sur ce métabolisme, et des polymorphismes, qui sont considérés comme étant neutres.Pour étudier l’influence de l’ADNmt sur le métabolisme énergétique, j’ai utilisé deux modèles d’étude : des cybrids portant des mutations de l’ADNmt retrouvées chez des patients atteints de surdité non-syndromique, et des cybrids portant des polymorphismes caractéristiques de l’haplogroupe J.Les résultats obtenus nous indiquent clairement que la différence entre des mutations pathogènes et des polymorphismes n’est pas aussi importante que ce qui était jusqu’à alors supposé. En effet, elle dépend d’un ensemble de facteurs tels que (i) le fonds génétique nucléaire et mitochondrial, (ii) de facteurs environnementaux. Car sous l’influence de ces différents facteurs une mutation considérée comme pathogène peut devenir neutre, et un polymorphisme considéré comme neutre peut devenir pathogène. / Mitochondria, intracellular organelles of eukaryotic organisms, provide most of the necessary energy for cellular activity through oxidative phosphorylation, synthesizing ATP (energy source for the cell) by a coupling between the respiratory chain and the ATPsynthase. These energy metabolism reactions are carried out by enzymatic complexes constituted by sub-units coded by both nuclear and mitochondrial DNA. It has been shown that activity defects in these complexes could be responsible for a group of pathologies under the name of mitochondrial cytopathies.One of the fundamental issues of the study of the mechanisms that lead to mitochondrial cytopathies is the understanding of the influence that mitochondrial DNA has over mitochondrial metabolism. Indeed, mitochondria have their own DNA, and mutations in this DNA are classified according to their impact on mitochondrial metabolism: pathological mutations, which have negative consequences on mitochondrial metabolism, and polymorphisms, which are considered to be neutral.In order to study the influence of mtDNA on energy metabolism, I used two different models: cybrid cells carrying mtDNA mutations found in non-syndromic hearing loss patients, and cybrid cells carrying polymorphisms defining haplogroup J.The results gathered in these studies show that the difference between pathological mutations and polymorphisms is not as big as previously believed. Indeed, it depends on several factors, such as the nuclear and mitochondrial genetic backgrounds, as well as the environmental factors, because under the influence of these factors a mutation considered as pathological may become neutral, and a polymorphism considered neutral may become pathological.

(in English) Pipistrellus pipistrellus species complex contains two sympatric species inhabiting Europe and part of West and Central Asia (Pipistrellus pipistrellus s. str, Pipistrellus pygmaeus s. str) and several other lines, isolated in the Mediterranean (North Africa, islands and peninsulas of the Mediterranean Sea). This taxon is a part of the extensive radiation within the genus Pipistrellus, which in today's concept includes about 30 species. Mosaic line of P. pipistrellus complex, located at different stages of diversification and secondary contacts in the Mediterranean biodiversity hotspot, is a suitable model for research on speciation. In this thesis we focused on analyses of distribution, phylogeography, population structure and demography based on mitochondrial data from 323 individuals, representing almost the entire range. Control region of mitochondrial DNA was chosen as a genetic marker. Variability in the 378 pb long fragment acknowledged the existence of several genetically distinct lines whose species status is discussed. Observed fylogeografic pattern confirms the existence of groups of radiation centers in the Mediterranean region. An allopatric speciation was there, two of the lines (P. pipistrellus s. str and P. pygmaeus s. str.) later expanded into Europe and their ranges...

Hybridisation between introduced and endemic species causes conservation concerns, but also provides us with an opportunity to study the dynamics of gene flow between two species as they first meet. Japanese sika deer (Cervus nippon) were introduced to the British Isles at a number of locations at the beginning of the 20th century. In the intervening time, sika have spread and their range now extends across approximately 40% of Scotland, where they overlap with that of native red deer (C. elaphus), with which they hybridise. In this study we focus on the consequences of one particular introduction that took place at Carradale, on the Kintyre Peninsula in 1893. First, I assessed the current state of hybridisation using a sample of 735 red and sika deer samples collected in 2006/7 from forestry blocks throughout the Kintyre Peninsula. Genetic analysis was conducted with a panel of 22 highly differentiated microsatellite loci and one mtDNA marker. Population admixture analysis of the microsatellite data was conducted with the Bayesian clustering programme STRUCTURE. Over most of the study area, levels of introgression into red and sika deer were low and were consistent with a scenario of very occasional F1 hybridisation followed by backcrossing. There was, however, one forestry block where 43% of individuals could be defined as hybrids. Second, I developed a branching process model of introgression via backcrossing, to assess whether variation in introgression across microsatellite loci could be interpreted as a signature of selection, or could in fact be attributed to stochastic processes. If only a few hybridisation events have contributed to the hybridising population, the pattern of introgression, even with a large number of genetic markers, will be highly stochastic. This pattern of neutral variation in introgression can have high enough variance that it could be mistaken for selection. Therefore, even if strong selection is acting, it may not be possible to distinguish its effects from neutral variation. Third, I analysed trends in hybridisation and introgression over 15 years on the peninsula, through analysis of a dataset of 1513 red and sika deer samples at 20 microsatellite and a mtDNA marker. There was little evidence of change in the extent of hybridisation and introgression over time. MtDNA introgression was predominantly from red deer into sika. Recent introgression into sika on the peninsula can be explained by a very small number of F1 hybridisation events (~10) via analysis of the number of alleles that have introgressed from polymorphic red deer into the genetically homogenous sika population (a similar analysis cannot be conducted for introgression into red deer). Finally, I conducted a regression analysis of genetic hybrid scores against phenotypic traits to assess the effect of hybridisation on phenotype. Hybridisation has caused changes in the weight of sika-like deer and red-like females. Hybridisation has caused changes in incisor arcade breadth of both populations and jaw length (a proxy for skeletal size) in sika-like females. However, there is no evidence that hybridisation has caused changes in kidney fat (a measure of condition) or pregnancy rates in either population. In conclusion, even a small number of F1 hybridisation events can lead to extensive introgression and the timing and spatial distribution of these events is likely to have a large impact on the structure of a recently hybridising population - stochastic factors dominate both the distribution of hybrid individuals and the distribution of the genes that introgress following a hybridisation event. In red deer and sika deer, increasing phenotypic similarities of the two populations caused by hybridisation are likely to facilitate further breakdown between the two species. It is possible that breakdown in assortative mating between the two species could occur across their range.