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O estudo da interação entre os indivíduos de uma mesma espécie ou de espécies diferentes é essencial para o entendimento das dinâmicas envolvidas na manutenção das comunidades ou assembléias na natureza. Assim, o estudo das preferências alimentares das larvas dos drosofilídeos, refletidas no padrão de emergência das mesmas dos sítios de oviposição, é de suma importância, uma vez que este grupo de organismos tornou-se um excelente modelo para o estudo de padrões ecológicos. Assim, esta tese busca identificar como as larvas de espécies de Drosophilidae se relacionam na utilização dos recursos tróficos, identificando quais os principais fatores que podem estar atuando na manutenção da diversidade de espécies de suas assembléias em áreas de Mata Atlântica e urbanas de Florianópolis (SC). Realizamos coletas de frutos em onze localidades do Estado de Santa Catarina, onde montamos uma listagem das espécies vegetais hospedeiras utilizadas como sítio de oviposição e das espécies de Drosophilidae que as utilizam. Observamos que as espécies de Drosophilidae colonizam os ambientes urbanos estudados, mas há uma perda de diversidade de espécies, evidenciada pela ausência de espécies raras nestas amostras. Ainda, as espécies de Drosophilidae coletadas apresentaram um caráter generalista quanto à utilização dos recursos tróficos, onde, nas assembléias de Mata Atlântica, verificou-se a formação de grupos ecológicos funcionais. Este tipo de organização não foi observado nas assembléias urbanas, onde há uma grande sobreposição dos nichos e uma menor diversidade de espécies. Além dos frutos, foram coletados também corpos de frutificação de fungos a fim de verificarmos as espécies de Drosophilidae emergentes dos mesmos. Dentre as espécies de moscas emergentes estão as dos gêneros Drosophila, Hirtodrosophila, Mycodrosophila e Leucophenga. Cabe ressaltar que as espécies neotropicais da radiação immigrans-tripunctata (gênero Drosophila) possuem a capacidade de colonizar fungos em ambientes preservados e alterados do bioma Mata Atlântica. Em outro estudo, buscamos verificar como a limitação de recursos alimentares para as larvas de drosofilídes pode influenciar a interação competitiva entre as mesmas. Para tal, foram coletados frutos de Buchenavia tomentosa (Combretaceae) e submetidos a dois tratamentos, um deles com uma suplementação alimentar. Assim, obtivemos evidências de que há restrições alimentares ou nutricionais em recursos naturais, que aumentam a interação competitiva entre espécies da família Drosophilidae. Entretanto, estas espécies possuem diferentes respostas à esta limitação, e o aumento da competição interespecífica parece ser maior que da intraespecífica. Finalmente, foi realizada uma revisão da ocorrência das espécies de Drosophilidae no Brasil, onde foram levantadas 304 espécies coletadas em nosso território. A maioria dos registros é de espécies do gênero Drosophila, o mais bem estudado da família. Os estados mais bem amostrados até o momento são São Paulo, Rio de Janeiro, Rio Grande do Sul e Santa Catarina, além do Distrito Federal, onde há grupos de pesquisa enfocando a ecologia e taxonomia das espécies de Drosophilidae. Esta revisão auxiliou na avaliação dos objetivos anteriores, contribuindo com um panorama do conhecimento e distribuição desta moscas no Brasil. / The study of the interaction among the individuals of a same species or of different ones is essential for the understanding of the dynamics involved in the communities or assemblies maintenance in nature. Thus, the study of the alimentary preferences of the drosophilids larvae, evidenciated by their emergency pattern of the breeding sites, is of highest importance once that this group of organisms became an excellent model for the study of ecological patterns. So, this thesis aimed to identify how the larvae of the Drosophilidae species use the trophic resources, identifying the main factors that can be acting in the maintenancement of the species diversity of assemblies in areas of Atlantic Rain Forest and urbanized of Florianópolis (SC). We collected fruits in eleven locations of the State of Santa Catarina, and we listed the vegetable host species used as breeding sites and the Drosophilidae species emerged of them. We observed that the Drosophilidae species colonize the studied urban environments, but there is a loss of species diversity, evidenced by the absence of rare species in these samples. Although, the collected Drosophilidae species presented a generalist character for the use of the trophic resources, where, the formation of functional ecological groups was verified in the assemblies of Atlantic Rain Forest. This kind of organization was not observed in the urban assemblies, where there are a high niche overlap and lower species diversity. Besides fruits collections, were carried out collections of fungi bodies of fructification in order to verify their emerging Drosophilidae species. Among the emerging fly species are the ones of the Drosophila, Hirtodrosophila, Mycodrosophila and Leucophenga genera. It to be useful to emphasize that the Neotropical species of the immigrans-tripunctata radiation (Drosophila genus) have capacity to colonize mushrooms in preserved Atlantic Rain Forest and antropic environments. In another study, we search for how the limitation in trophic resources for drosophilid larvae could influence the competitive interaction among them. For such, fruits of Buchenavia tomentosa (Combretaceae) were collected and submitted to two treatments, one of them with an alimentary supply. Thereby, we obtained evidences that there are alimentary or nutritional restrictions in natural resources, which increase the competitive interaction among species of the family Drosophilidae. However, these species have different answers to this limitation, and the increase of the interspecific competition seems to be larger than of the intraspecific. Finally, a revision of the occurrence of the Drosophilidae species in Brazil was accomplished, where were found 304 species recorded in our territory. Most of the records is of species of the Drosophila genus, the best studied of the family. The better evalueted states until the moment are São Paulo, Rio de Janeiro, Rio Grande do Sul and Santa Catarina, besides Distrito Federal, where there are research groups focusing the ecology and taxonomy of the Drosophilidae species. This revision helped us in the evaluation of the previous objectives, contributing with a panorama of the knowledge and distribution of these flies in Brazil.

"June 2003". / Bibliography: p. 189-196. / xv, 196 p. : ill. (some col.), plates (col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis aimed to characterise the G1-S phase role of Drosophila Eb1, dEb1, which was identified in a cyclin E genetic screen. A dominant modifier screen was undertaken to identify novel regulators of cyclin E, and cell cycle progression using a hypomorphic allele of cyclin E. One suppressor from this screen, Su(DmcycEjp)2.5, was identified as a potential Drosophila homologue of the microtubule binding protein Eb1, dEb1. Southern and northern analysis confirmed that Su(DmcycEjp)2.5 is an allele of dEb1, and other dEb1 alleles were shown to also be able to suppress cyclin Ejp. / Thesis (Ph.D.)--University of Adelaide, School of Molecular and Biomedical Sciences, 2003

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Thesis (Ph. D.)--University of Oregon, 2006. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 101-115). Also available for download via the World Wide Web; free to University of Oregon users.

The telomeres of most organisms are characterized by a protein-capping complex that protects chromosome ends, a series of repetitive subtelomeric sequences known as Telomere-Associated Sequences (TAS), and a behavioral phenomenon known as Telomere Position Effect (TPE). TPE is a phenomenon whereby normally active genes become repressed and silenced if relocated near to telomeres, and is thought to be a property of the proteins that constitute telomeric heterochromatin. Genetic dissection was used to exploit this phenomenon in order to identify components of telomeric heterochromatin in Drosophila melanogaster. Using genetic dissection, followed by a chromatin analysis technique known as Chromatin ImmunoPrecipitation (ChIP) I was able to identify three proteins, HDAC1, SU(VAR)3-9, and HP1c, as integral components of telomeric heterochromatin in Drosophila. HDAC1 and SU(VAR)3-9 are both believed to be involved in the gene-silencing process, and thus, their presence at telomeres could explain the phenomenon of TPE. Furthermore, I found that these proteins were specifically associated with the TAS region on the centromere-proximal side of the HeTA transposable elements that maintain telomere length in Drosophila. As a result of this, I proposed a model, which I call the ‘pairing-sliding model of telomere length control in Drosophila,’ which proposes that temporary incorrect pairing of Drosophila telomeres results in the deacetylation and subsequent methylation of the nucleosomes associated with the HeT-A and TART elements by TAS-associated HDAC1 and SU(VAR)3-9, resulting in these elements being transcriptionally silent. Thus, I propose that the TAS region, and the HDAC1 and SU(VAR)3-9 associated with it play a role in the negative regulation of telomere length in Drosophila.

Yeast SMT3 (Suppressor of Mif2 temperature sensitive mutant 3) is a Mif-related prortein, and is first found in suppression Mif2 (Mitotic fidelity of chromosome transmission protein 2) mutant. So far, among animals of higher level, we have found the existence of 3 SMT3 isozymes (A,B,C). It¡¦s known that SMT3A is located on chromosome 21. And smt3 sequence of Drosophila is similar to those of yeast or human in a percentage of 55%, 73%, and 52%. We analyze 10 strains of flies with p element inserted into position 27C6-8 on chromosome 21 and found a p element mutant, P997, near the position of smt3 gene. Then we built fly¡¦s smt3 mutation stock by using P element technology, and by using PCR, we can sieve out mutant fly fast and massively. Thus we can observe the expression of smt3 during the development of fly. The P element of stock 11378 is inserted 300bp before smt3 start codon. After stock 11378¡¦s crossing with W1118, we get smt3-null mutation. Then we found that smt3-null mutation is a recessive lethal mutant, fly will die in the forth period of embryo development. At that time, the cell nucleus has divided for about 10 to 13 times, also means 90 to 120 minutes after the embryo is produced. We also found two important characteristics about dead embryo of smt3-null mutation: (1) The DNA in the embryo is scattered and couldn¡¦t be condensed in the nucleus. (2) Huge and abnormally-dispersed vacuoles are observed in the embryo.