Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-04-04T14:58:46Z No. of bitstreams: 1 lidianecristinadasilva.pdf: 3867090 bytes, checksum: 57d0e38e146d3d14d2d9eccc6cd6cbe6 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-04-04T15:39:27Z (GMT) No. of bitstreams: 1 lidianecristinadasilva.pdf: 3867090 bytes, checksum: 57d0e38e146d3d14d2d9eccc6cd6cbe6 (MD5) / Made available in DSpace on 2017-04-04T15:39:27Z (GMT). No. of bitstreams: 1 lidianecristinadasilva.pdf: 3867090 bytes, checksum: 57d0e38e146d3d14d2d9eccc6cd6cbe6 (MD5) Previous issue date: 2009-02-18 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Apesar da diversidade e importância os moluscos terrestres têm sido pouco estudados, principalmente as espécies da malacofauna brasileira como é o caso de Bulimulus tenuissimus. Assim, objetivou-se com esse trabalho descrever a história de vida dessa espécie, através da avaliação do crescimento, reprodução e longevidade. Avaliou-se também a influência do isolamento sobre esses aspectos e a variação dos recursos energéticos em diferentes fases da vida, e nas diferentes estações do ano. Para tanto, foi realizado o acompanhamento do ciclo biológico de 240 moluscos, dos quais 120 foram mantidos em grupos e 120 foram mantidos em isolamento durante todo o ciclo de vida. Bulimulus tenuissimus apresentou grande plasticidade na forma de alocação de energia entre crescimento, reprodução e sobrevivência de acordo com a forma de criação, sendo a reprodução e longevidade maior para os animais mantidos em grupos, enquanto o crescimento foi mais acentuado nos isolados. Essa diferenciação no investimento energético levou a padrões de história de vida distintos nos dois grupos. Os moluscos de diferentes idades apresentam formas diferenciadas para alocação dos polissacarídeos avaliados, sendo a variação provavelmente relacionada ao estado reprodutivo dos moluscos. Além disso, constatou-se também que as reservas energéticas dos músculos são disponibilizadas e degradadas tanto na fase Adulta quanto na fase Senescente. O conteúdo de carboidratos variou de acordo com a idade, sendo a tal variação provavelmente relacionada ao estado reprodutivo dos animais. Também houve variação sazonal do conteúdo de glicogênio e galactogênio, os quais são coincidentes com o ciclo reprodutivo de B. tenuissimus, evidenciando-se que a sazonalidade reprodutiva parece ser controlada por fatores metabólicos. / There are few studies about land snails despite their importance and diversity, especially native species, such as Bulimulus tenuissimus. Thus, the objectives of this study were to describe the life history of this species evaluating the growth, reproduction and longevity. The influence of the isolation on these aspects, the change of energy resources in different ages and in different seasons were evaluated. For this purpose, there was monitoring the biological cycle of 240 snails, of which 120 were kept in groups and 120 were kept isolated during their lifetime. Bulimulus tenuissimus showed plasticity in the allocation of energy between growth, reproduction and survival. Growth of isolated snails was higher fecundity and longevity than the animals kept in isolation. However, the growth was high in isolation. Thus, the differential energetic investment has lead to distinct patterns of life history. The age influenced the allocation de glycogen and galactogen. However, there was not reduction of glycogen content in the digestive gland. It is suggest that the energy used in reproduction is acquired from food ingestion. There were seasonal changes on the contents these polysaccharides, which are coincident with the reproductive cycle of B. tenuissimus. This result showed that the reproductive seasonality of this species would be controlled by metabolic factors.

Différentes approches ont été utilisées pour évaluer les effets de deux formes de nanoparticules de carbone (NPC), nanotubes et graphène, afin de comprendre les mécanismes de la réponse générée par la diatomée benthique d'eau douce Nitzschia palea. Les effets à l'échelle de la communauté ont démontré un impact temporaire sur la croissance du biofilm et une accumulation des NPC dans la matrice extracellulaire. L'application d'une étude transcriptomique a mis en évidence l'importance de l'interaction physique, à l'origine d'altération du frustule, dans la mise en place de cette réponse extracellulaire se traduisant par une surproduction des substances exo-polymériques (EPS). Cette approche a également révélé l'impact des NPC sur l'activité photosynthétique des diatomées et une modification du métabolisme énergétique, suggérant une allocation énergétique en faveur de la production d'EPS. L'étude du protéome extracellulaire a permis d'avoir un premier aperçu de la composition de la matrice extracellulaire, principalement constituée de protéines à caractère hydrophobe. Lors de l'exposition aux NPC, les diatomées semblent produire un système adhésif complexe permettant de renforcer la matrice extracellulaire et d'augmenter la stabilité du biofilm tout en piégeant les NPC. L'exposition des diatomées face au deux formes de NPC induit une réponse présentant une forte similitude notamment pour les plus fortes concentrations testées. / Different approaches were used to assess the effect of two forms of carbon-based nanoparticles (CNP) nanotubes and graphene, in order to determine the mechanism of the response generated by the benthic freshwater diatom Nitzschia palea. The effect at the cellular community scale demonstrated a temporary impact on biofilm growth and an accumulation of NPC in the extracellular matrix. The use of transcriptomic study evidenced the role of the physic interaction, causing alteration of the frustule, in the extracellular response leading to an overexcretion of exopolymeric substances (EPS). This approach also revealed the impact of NPC on the photosynthetic activity of diatoms and a modification of the energetic metabolism suggesting an energetic allocation for the EPS production. The study of the extracellular proteome allowed to have a first insight of the extracellular matrix composition, in majority composed of hydrophobic-like proteins. In NPC exposure, diatoms seemed to produce an adhesive system allowing to strengthen the extracellular matrix and increase the biofilm stability while trapping NPC. The exposition of diatoms to the two NPC forms induce a response greatly similar for the highest tested concentration.