Made available in DSpace on 2014-06-12T15:03:07Z (GMT). No. of bitstreams: 2 arquivo1210_1.pdf: 3294326 bytes, checksum: 9fc990b48e1446999fb6ce37e99cda14 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2008 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Nematoda é um dos táxons mais abundantes e diversos dentre os metazoários, contudo, grande parte desta diversidade permanece desconhecida. A taxonomia do grupo muitas vezes tem uma história controversa, não somente em conseqüência do desenvolvimento dos procedimentos em sistemática, mas também por que relativamente poucos nematologistas produzem classificações detalhadas. Além disso, Nematoda é considerado um grupo de difícil identificação, devido ao seu tamanho corporal, o que reforça a necessidade da utilização de outros subsídios para acelerar a descoberta e classificação de sua biodiversidade. A fim de pôr em prática a taxonomia integrativa , onde vários tipos de dados são utilizados no estudo das espécies, este trabalho destinase a descrever uma nova espécie de Daptonema, revelar as suas relações filogenéticas, além de descrever e correlacionar sua estratégia reprodutiva com os parâmetros ambientais. As coletas de material biológico e dados abiótico foram realizadas na Bacia do Pina, quinzenalmente, na estação seca (setembro, outubro e novembro/2006) e na estação chuvosa (maio, junho e julho/2007), sempre na baixa-mar. Em dezembro, coletou-se uma amostra para extração de DNA e sequenciamento do gene 18S (rDNA). As seqüências foram analisadas pelos métodos de máxima parcimônia, neighbor-joining e inferência bayesiana. As correlações com os fatores ambientais foram realizadas utilizando a Correlação de Spearman. A espécie de Daptonema é nova por apresentar uma acentuada redução das setas cefálicas e a espícula em linha reta, característica esta que requer uma emenda na descrição do gênero. Em algumas fêmeas também se pode observar a incubação intra-uterina da prole, sendo tal característica considerada uma das autapomorfias da espécie. As análises apoiaram Daptonema sp. nov. como uma linhagem genética e evolutivamente distinta. Os dados também indicaram uma sinonímia e uma parafilia envolvendo Daptonema. Em Daptonema sp. nov. foi observado a ovoviviparidade, entretanto, o que torna o fenômeno peculiar é a presença de ovos e juvenis em vários estágios de desenvolvimento. Os resultados ecológicos mostraram que nenhum fator ambiental apresentou uma correlação significativa com o fenômeno reprodutivo em Daptonema sp. nov

No description available.

>Magister Scientiae - MSc / The extreme conditions of Antarctic desert soils render this environment selective towards a diverse range of psychrotrophic microbial communities. Cracks and fissures in translucent quartz rocks permit an adequate amount of penetrating light, sufficient water and nutrients to support cryptic microbial development. Hypolithons colonizing the ventral surface of these quartz rocks have been classified into three types: cyanobacterial dominated (Type I),moss dominated (Type II) and lichenized (Type III) communities. Eukaryotic microbial communities were reported to represent only a minor fraction of Antarctic communities. In this study, culture independent techniques (DGGE, T-RFLP and clone library construction) were employed to determine the profile of the dominant eukaryotes, fungi and microalgae present in the three different hypolithic communities. The 18S rRNA gene (Euk for eukaryotes), internal transcribed spacer (ITS for fungi) and microalgal specific regions of the 18S rRNA gene, were the phylogenetic markers targeted for PCR amplification from hypolith metagenomic DNA. Results suggest that the three hypolith types are characterized by different eukaryotic, fungal and microalgal communities, as implied by nMDS analysis of the DGGE and T-RFLP profiles. Sequence analysis indicates close affiliation to members of Amoebozoa, Alveolata, Rhizaria (general eukaryote), Ascomycota (fungal) and Streptophyta (microalgal). Many of these clones may represent novel species. This study demonstrates that Dry Valley hypolithons harbour higher eukaryote diversity than previously recognised.Each hypolithon is colonized by specialized microbial communities with possible keystone species. The ecological role of the detected microorganisms in the hypolith environment is also theorized, and a trophic hierarchy postulated.

Lake Baikal, in Siberia, Russia, contains the highest biodiversity of any extant lake, including an impressive radiation of gammaroidean amphipods that are often cited as a classic case of adaptive radiation. However, relationships among Baikal's amphipods remain poorly understood. The phylogenetic history of 32 Lake Baikal amphipod species, representing most major lineages of the endemic fauna, was examined using three genes (COI, 16S rRNA, and 18S rRNA), and 152 morphological characters. Results support monophyly of the largest and most diverse of the Baikalian families, the Acanthogammaridae. Analyses suggest that a second Baikalian family, the fossorial Micruropodidae, is paraphyletic and composed of two divergent clades, one of which includes Macrohectopus branickii, a morphologically specialized pelagic planktivore traditionally assigned its own family. The extreme morphological and ecological divergence of Macrohectopus from its close genetic relatives, and conversely, the large genetic distances among other morphologically similar micruropodids, suggest that morphological and molecular evolution have often been uncoupled during the radiation of Baikal's amphipods. This study suggests that the amphipod fauna of Lake Baikal is polyphyletic; originating from two independent invasions of the lake.

No description available.

京都大学 / 新制・課程博士 / 博士(理学) / 甲第24083号 / 理博第4850号 / 新制||理||1694(附属図書館) / 京都大学大学院理学研究科生物科学専攻 / (主査)教授 緒方 博之, 教授 高田 彰二, 教授 望月 敦史 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

Dans les océans, les microbes sont à la base de la chaîne alimentaire et sont essentiels aux cycles biogéochimiques marins. Le domaine de l'écologie marine moléculaire a révélé que les microbes eucaryotes présentent une grande diversité à tous les rangs taxonomiques. Des recherches étudiant le gène ARNr 18S à partir de l'ADN ont fourni des informations phylogénétiques sur les communautés microbiennes eucaryotes dans l'océan Arctique. Ce projet constitue la première étude portant sur la diversité de ces communautés à partir des transcrits d'ARNr. Ces transcrits ont révélé l'identité taxonomique des communautés microbiennes eucaryotes actives dans cette région sensible aux changements climatiques. En plus, ceci est la première étude, en haute mer, de la nitrate réductase assimilatrice (NR), un gène eucaryote fonctionnel clé. La comparaison entre l'ADN et l' ARN fourni de l'information sur l'histoire des masses d'eau et permet de lier la taxonomie et l'activité dans un environnement naturel.

Le jujubier (ou Ziziphus mauritiana Lam.) est une espèce à usages multiples (fruits, fourrage, bois de service) prioritaire pour le reboisement et l’arboriculture fruitière dans le Sahel. Dans ce contexte où les sols sont souvent dégradés et pauvres en minéraux (P en particulier), la mycorhization et la fertilisation phosphatée pourraient jouer un rôle important dans l’amélioration de la croissance et de la productivité des jujubiers.L’objectif principal de ce travail était d’améliorer la croissance et la production fruitière de Z. mauritiana par l’inoculation mycorhizienne dans deux vergers au Sénégal. Il avait pour objectifs spécifiques (i) d’évaluer les réponses à l’inoculation avec des CMAs de différentes espèces de Ziziphus et de provenances de Z. mauritiana en serre, (ii) d’évaluer l’impact de l’inoculation avec R. irregularis IR27 sur la croissance, la survie et la production fruitière de Z. mauritiana, (iii) d’évaluer l’impact de l’inoculation sur la diversité des communautés de CMAs associés à Z. mauritiana en plantation et (iv) de déterminer la persistance de R. irregularis IR27 dans les racines de Z. mauritiana en plantation. Le champignon R. irregularis IR27 s’est avéré le plus efficace parmi les CMAs testés dans ce travail. Le couple Z. mauritiana /R. irregularis IR27 a donc été choisi comme modèle pour étudier l’impact de l’inoculation sur la production fruitière de deux provenances, Gola (variété indienne sélectionnée pour ses fruits de grosse taille) et Tasset (provenance locale à fruits de petite taille) dans deux sites contrastés (Amally et Keur Mangari). Nos résultats ont montré un effet positif de l’inoculation sur la croissance, la survie et le taux de mycorhization de Z. mauritiana à 13 et 24 mois respectivement à Amally et à Keur Mangari. L’inoculation a également augmenté la production fruitière des jujubiers à 18 et 30 mois de plantation à Keur Mangari. Ces résultats montrent la grande capacité de R. irregularis IR27 à compétir face aux CMAs indigènes. Le séquençage Illumina MiSeq du gène 18S a permis de révéler un impact négatif de l’inoculation sur la diversité et la richesse des communautés de CMAs natifs à Amally contrairement à Keur Mangari où l’inoculation n’a pas eu d’impact ni sur la diversité ni sur la richesse des CMAs. Le gène RPB1 s’est révélé pertinent comme marqueur pour détecter R. irregularis IR27 dans les racines de Z. mauritiana inoculés et évaluer par qPCR l’intensité de la colonisation racinaire des jujubiers par R. irregularis IR27 qui a représenté 11 à 13% à 13 mois de plantation à Amally et 12 à 15% à 24 mois de plantation à Keur Mangari. Cependant, il s’avère important d’évaluer à plus long terme l’impact de R. irregularis IR27 et son devenir dans les racines de Z. mauritiana en plantation dans une large gamme de conditions environnementales. / The jujube (or Ziziphus mauritiana Lam.) is an important multipurpose species (e.g. fruits, fodder, wood) for reforestation and fruit farming in the Sahel. In this context where soils are often degraded and deficient in P, mycorrhization and phosphorus fertilization could play a major role on improvement of jujube growth and productivity. The main objective of this work was to improve growth and fruit production of Z. mauritiana by mycorrhizal inoculation in two orchards at Senegal. This work aims (i) to evaluate the responses of different species of Ziziphus and provenances of Z. mauritiana to inoculation with AMF in greenhouse conditions, (ii) to assess the impact of inoculation with R. irregularis IR27 on growth, survival and fruit production of Z. mauritiana, (iii) to assess the impact of inoculation on diversity of native AMF communities associated to Z. mauritiana after planting and (iv) to determinate the persistence of R. irregularis IR27 in roots of Z. mauritiana after planting.The fungus R. irregularis IR27 proved to be the most effective AMF tested in this work. The pair Z. mauritiana /R. irregularis IR27 has been chosen as model to study the impact of inoculation on fruit production of two provenances, Gola (Indian variety selected for its large size fruits) and Tasset (local cultivar with small-sized fruits) in two sites with contrasting rainfall (Amally and Keur Mangari). Our results showed a positive effect of inoculation on growth, survival and mycorrhizal colonization of Z. mauritiana plants at 13 and 24 months after planting at Amally and Keur Mangari respectively. Inoculation increased also fruit production of jujubes at 18 and 30 months after planting at Keur Mangari. These results indicated the high ability of R. irregularis to compete with indigenous AMF. The MiSeq Illumina sequencing of 18S rRNA gene revealed a negative impact of inoculation on AMF richness and diversity at Amally, unlike at Keur Mangari where inoculation had no impact on AMF richness and diversity. The RPB1 gene proved to be an appropriate marker to detect of R. irregularis IR27 in inoculated Z. mauritiana roots and to evaluate by qPCR the root colonization of R. irregularis IR27 which accounted for 11 to 13% at 13 months after planting at Amally and 12 to 15% at 24 months after planting at Keur Mangari. Therefore, it is important to assess at long-term the impact of R. irregularis IR27 and its persistence in inoculated Z. mauritiana roots in large environmental conditions.

Made available in DSpace on 2017-07-10T14:38:17Z (GMT). No. of bitstreams: 1 Leonardo.pdf: 1018615 bytes, checksum: 9f57d9963ee3262c7c62a9c0e4dc3cfe (MD5) Previous issue date: 2013-03-04 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Fish represent the largest group and occupy a more basal position in the phylogeny of vertebrates, contain large morphological variety and are present in different habitats, making it an interesting model for the study of genetic variability and evolution. Among these, for species popularly known as minnows, growing numbers of systematic and phylogenetic studies are presented, primarily due to the discovery of synonyms and description of new species. In the present study we analyzed cytogenetically seven species of minnows (abramis A., A. asuncionensis, A. correntinus, Astyanax sp., M. dichroura, R. and T. descalvadensis argenteus) collected downstream of the Iguazu Falls (Lower Basin Paraná River), and this stretch corresponding to the area of environmental preservation of the Iguassu National Park. It is species-specific markers, such as karyotypic macrostructure, pattern of heterochromatin distribution and localization of 5S rDNA genes and 18S rDNA. The results help to distinguish between A. abramis and A. asuncionensis, the first cytogenetic data of A. correntinus suggested correlation with group A. schubarti due to the high similarity of karyotypes. The analysis astyanax sp. confirmed case of a species not yet described taxonomically. The analyzes Moenkhausia, Roeboides Tetragonopterus and showed the first molecular cytogenetic data, revealing variability in the number and location of sites of 5S rDNA and 18S rDNA, confirming the diversity of these genes among different genera of Characidae, and allowing the use of these markers in comparative analyzes with congeneric species / Os peixes representam o grupo mais numeroso e ocupam a posição mais basal na filogenia dos vertebrados, comportam grande variedade morfológica e estão presentes em diversos habitats, tornando-se um grupo interessante para o estudo da variabilidade genética e evolução. Dentre estes, para espécies popularmente conhecidas como lambaris, crescentes números de estudos sistemáticos e filogenéticos são apresentados, principalmente decorrente da descoberta de sinonímias e descrição de novas espécies. No presente estudo foram analisadas citogeneticamente sete espécies de lambaris (A. abramis, A. asuncionensis, A. correntinus, Astyanax sp., M. dichroura, R. descalvadensis e T. argenteus) coletadas à jusante das Cataratas do Iguaçu (Bacia do Baixo rio Paraná), sendo este trecho correspondente a área de preservação ambiental do Parque Nacional do Iguaçu. Verificou-se marcadores espécie-específicos, como macroestrutura cariotípica, padrão de distribuição da heterocromatina e localização dos genes 5S rDNA e 18S rDNA. Os resultados auxiliaram na diferenciação entre A. abramis e A. asuncionensis; os primeiros dados citogenéticos de A. correntinus sugeriram correlação com o grupo A. schubarti devido à alta similaridade cariotípica. A análise de Astyanax sp. confirmou tratar de uma espécie ainda não descrita taxonomicamente. As análises em Moenkhausia, Roeboides e Tetragonopterus evidenciaram os primeiros dados citogenéticos moleculares, revelando variabilidade quanto ao número e localização dos sítios de 5S rDNA e 18S rDNA, confirmando a diversidade destes genes entre os diferentes gêneros de Characidae, e possibilitando a utilização destes marcadores em análises comparativas com espécies congêneres

Des recherches en sciences judiciaires ont montré récemment une possible corrélation entre le temps d’entreposage d’échantillons de fluides corporels et la dégradation de l’ARN dans ceux-ci. Le moment où une tache a été déposée sur une scène de crime peut être important pour déterminer la pertinence d’un échantillon dans une enquête. Dans ce mémoire, nous rapportons les profils de dégradation de quatre ARN différents mesurés par RT-qPCR, soit l’ARN ribosomique 18S et les ARNm de la β-actine, de la glyceraldehyde-3-phosphate déhydrogénase et de la cyclophiline A, obtenus de taches de sang, de salive et de sperme, entreposés à la température de la pièce ou au congélateur à -80°C sur une période de 6 mois. Nos résultats montrent une faible variation interindividuelle pour le sang et le sperme, mais une différence importante entre les donneurs pour la salive. De plus, le profil de dégradation est semblable pour tous les transcrits, mais diffère entre les fluides. La congélation des échantillons stabilise les ARN avant leur analyse. Finalement, la quantité d’ARN détecté est en relation avec le temps d’entreposage et pourrait être utilisée afin d’estimer l’âge des échantillons lorsque l’impact des conditions d’entreposage sur la dégradation de l’ARN sera mieux connu. / Recent studies in forensic science have shown a possible correlation between the degradation rate of some RNA transcripts and the age of bloodstains. The time of deposition of a stain can be of major importance to determine the relevance of a sample in a forensic investigation. In this thesis, we describe the degradation profiles of the 18S ribosomal RNA and the β-actin, glyceraldehyde-3-phosphate dehydrogenase and cyclophilin A mRNAs, measured by RT-qPCR and obtained from dried blood, semen and saliva stains stored at room temperature or frozen at -80°C up to 6 months. Our results showed low inter-individual variation for blood and semen stains, but a high variation was observed between donors for saliva. Moreover, degradation profile of each transcripts was similar, but differed between fluids. Freezing samples prevented RNA degradation over time. Finally, RNA quantity was in relation with the time of storage and could be used to estimate the time since deposition of a stain when the effects of various storage conditions on RNA degradation profiles will be better documented. / Projet de recherche réalisé en collaboration avec la section Biologie/ADN du Laboratoire de sciences judiciaires et de médecine légale (LSJML) de Montréal.