The phaseolin (phas) promoter drives the copious production of transcripts encoding the protein phaseolin during seed embryogenesis but is silent in vegetative tissues when a nucleosome is positioned over its three phased TATA boxes. Transition from the inactive state in transgenic Arabidopsis leaves was accomplished by ectopic expression of the transcription factor PvALF (Phaseolus vulgaris ABI3-like factor), and application of abscisic acid (ABA). PvALF belongs to a family of seed-specific transcriptional activators that includes the maize viviparious1 (VP1) and the Arabidopsis abscisic acid-insensitive3 (ABI3) proteins. The major goal of the study is to gain insight to the regulation of seed-specific gene expression in three different aspects. First, since ABI3 (homolog of PvALF) is involved in ABA-mediated expression of several seed-specific protein genes in Arabidopsis, understanding its transcriptional regulation will provide insight to the mechanism by which PvALF expression is controlled. To achieve this, ABI3 promoter deletion analysis using either $-glucuronidase (gus) or green fluorescent protein (gfp) reporter gene fusions have identified various regulatory regions within the ABI3 promoter including two upstream activating sequences and a minimal seed specific expression region. In addition, a 405 bp 5' UTR was shown to play a negative role in ABI3 expression, possibly through post-transcriptional mechanisms. Second, placement of PvALF expression under control of an estradiol-inducible promoter permitted chronological ChIP analysis of changes in histone modifications, notably increased acetylation of H3-K9, as phas chromatin is remodeled (potentiated). A different array of changes (trimethylation of H3-K4) is associated with ABA-mediated activation. In contrast, H3-K14 acetylation decreased upon phas potentiation and increased on activation. Whereas decreases in histone H3 and H4 levels were detected during PvALF-mediated remodeling, slight increases occurred following ABA-mediated activation, suggesting the restoration of histone-phas interactions or the redeposition of histones in the phas chromatin. The observed histone modifications thus provide insight to the factors involved in euchromatinization and activation of a plant gene. Finally, ectopically expressed ABI5 and PvALF renders the activation of phas ABA-independent, suggesting ABI5 acts downstream of ABA during phas activation.

Spt6 is a conserved eukaryotic transcription factor, known to interact with both nucleosomes and RNA polymerase II (RNAPII) to control transcription. We have initiated study of Spt6 in S. pombe in order to identify both novel and conserved roles in regulation of transcription and chromatin. We first constructed and analyzed spt6 mutants by several approaches. As Spt6 is known to be required for histone H3K36 methylation in both Saccharomyces cerevisiae and human cells, we examined the global levels of several histone modifications; we found that in S. pombe, Spt6 is required for both H3K4 and H3K36 trimethylation. We examined the chromatin state at two highly expressed genes, \(act1^+\) and \(pma1^+\), and found that there is a defect in recruitment of the methyltransferases responsible for those marks, Set1 and Set2, respectively. We also observed loss of nucleosomes, as well as a decrease in histone H2B monoubiquitylation. These results suggest that Spt6 plays an important role in chromatin regulation during transcription. We also conducted transcriptional analysis of an spt6 mutant by both microarray and high-throughput sequencing (RNA-seq) and discovered that Spt6 plays a critical role in maintaining the integrity of transcription genome-wide. We found that Spt6 is required to repress antisense transcription, with nearly 70% of genes having antisense transcripts increased by at least two-fold in an spt6 mutant. We also found that transcription of most long terminal repeats (LTRs) is derepressed. Finally, we found that a major class of transcripts elevated in the spt6 mutant is derived from heterochromatin, which is normally silenced. To study the heterochromatic silencing defect in greater detail, we analyzed the chromatin state of the pericentric repeats and found a decrease in H3K9 trimethylation, elevated levels of H3K14 acetylation, reduced recruitment of several known silencing factors and a loss of siRNA production. We also see a very modest increase in RNAPII recruitment. Based on this combination of phenotypes, Spt6 is likely to contribute to both transcriptional and post-transcriptional silencing mechanisms. Taken together, we have found that Spt6 plays several important roles to control transcription in both euchromatin and heterochromatin in S. pombe.

The class II Transactivator (CIITA) is the master regulator for Major Histocompatibility Class II (MHC II) molecules. CIITA is dynamically regulated by a series of Posttranslational Modifications (PTMs). CIITA is responsible for initiating transcription of MHC II genes, thus allowing peptides derived from extracellular antigens to be presented to CD4+ T cells. CIITA’s PTMs are necessary for regulation of CIITA’s location, activity, and stability. Our work identifies the kinase complex ERK1/2 as being responsible for phosphorylating the previously identified regulatory site, serine (S) 280 on CIITA. Phosphorylation by ERK1/2 of CIITA S280 leads to increased levels of CIITA mono-ubiquitination and overall increases in MHC II activity. We further identify a novel ubiquitin modification on CIITA, lysine (K) 63 linked ubiquitination poly ubiquitination. Our data shows novel crosstalk between K63 ubiquitination and ERK1/2 phosphorylation. K63 ubiquitinated CIITA is concentrated to the cytoplasm, and upon phosphorylation by ERK1/2, CIITA translocates to the nucleus, thus demonstrating that CIITA’s location and activity is regulated through PTM crosstalk. While ubiquitination has been shown to be a critical PTM in the regulation of CIITA, the enzyme(s) mediating this important modification remained to be elucidated. Previous reports implicating the histone acetyltransferase (HAT), pCAF as an ubiquitin E3 ligase were intriguing, as pCAF is also known to participate in the acetylation of both histones at the MHC II promoter and in acetylation of CIITA. We now identify novel roles for pCAF in the regulation of CIITA. We show pCAF acts as an E3 ligase, mediating mono, K63, and K48 linked ubiquitination of CIITA. We therefore demonstrate an additional substrate for the “dual acting” enzyme, pCAF. In sum, our observations identify enzymes involved in both the phosphorylation and ubiquitination of key residues of CIITA, which ultimately regulate CIITA activity. Together our observations contribute to knowledge of CIITA’s growing network of PTMs and their role in regulating the adaptive immune response, and will allow for development of novel therapies to target dysregulated CIITA activity during adaptive immune responses.

Thèse (Ph. D.)--Université Laval, 1997. / Bibliogr.: f. 115-121. Publié aussi en version électronique.

The chief objective of this dissertation is the description of tone realization differences in Hanoian and Saigonese dialects based on a representative sample of recorded material, with special focus on read monologue and semi-spontaneous conversational speech. The research discusses mainly issues of tone production but it is complemented by a section on tone perception in form of a perception test. The theoretical background in Section 2.1. describes the topic of tonality and tonal languages in general. Section 2.2. is devoted to the description of the Vietnamese language and attention is specifically paid to tonal inventories of both researched dialects. Tonogenesis is mentioned on a general level as well as in the Vietnamese language in particular. Chapter 3 introduces the research methodology, namely the speaker selection, speech material preparation and recording, data extraction and preparation for the analyses and the perception test. Chapter 4 is divided into three sections. Section 4.1. speaks about tone realizations in isolation and carefully preselected context. Its goal is to investigate the behaviour of tonal contours influenced by as few variables as possible. The results should be comparable to the findings of previously conducted studies. Section 4.2. strives to assess data from a...

The purpose of this survey was to find patterns in methods elementary general music teachers use to create a successful environment in the inclusive music classroom. Twenty-four participants completed the survey. The most frequently used accommodation and modification methods were considered a part of the participants' regular teaching practice. The participants also indicated they did not collaborate with other teachers very often, which conflicted with findings from other studies. Further research would benefit from a larger sample size to make results more generalizable.

Repo-Man is a chromatin-associated PP1 targeting subunit that coordinates chromosome re-organisation and nuclear envelope reassembly during mitotic exit. At the onset of mitosis, Repo-Man association with the chromosomes is very dynamic; at anaphase, Repo-Man targets to the chromatin in a stable manner and recruits PP1 to de-phosphorylate histone H3 at Thr3, Ser10 and Ser28. Previous studies have suggested that CDK1 and AuroraB are the kinases responsible for the inactivation of the complex and for its dispersal at the onset of mitosis respectively. We have previously shown that the binding of Repo-Man to PP1 is decreased in mitosis and we have identified a region adjacent to the RVTF motif that contains multiple mitotic phosphosites (RepoSLIM). This region is conserved only in another PP1 targeting subunit: Ki-67. In order to understand the importance of this region for the complex formation and stability, we have conducted mutational analyses on several residues, and addressed their contribution towards Repo-Man chromosome targeting and PP1 binding in vivo. We have identified new sites in Repo-Man that, when phosphorylated, contribute to the weakening of the binding between Repo-Man and PP1. Interestingly, our results also indicate that several kinases are involved in the mitotic regulation of the complex. We have also identified Lamin A/C as a Repo-Man substrate and introduced a new model for Lamin A/C regulation at interphase. Furthermore, we identified Repo-Man as a marker of malignancy in tripe egative breast cancer, which controls cell movement and levels of important oncogenic markers Aurora A and C-Myc, and propose Repo-Man/PP1 complex as a therapeutic target for the treatment of triple negative breast cancer through the newly identified RepoSLIM.

Since the first explorations at the Paracas Peninsula in the beginnings of the 20th Century, cranial modifications drew attention of archaeologists. Several descriptions and classifications have been proposed, as well as hypothesis regarding the reasons behind this cultural practice; generally elements of identity such as status, gender, origin and ethnicity.Nevertheless, none of these hypothesis have been demonstrated yet, since there are not systematic studies correlating cranial shapes with archaeological provenience. In the context of the increasing interest regarding the Late Formative social and political dynamics in the South Coast of Peru, the identity of people buried in the Paracas Peninsula cemeteries and their possible relations to populations that inhabited the valleys towards the north and south is a central issue that has been addressed from the study of objects associated to the burials. Nevertheless the study of human remains is crucial and since the DNA preservation in coastal archaeological context is not good, the study of cranial modifications can give important information. In this paper we study and classify the cranial shapes of 38 individuals coming from 35 Paracas mortuary contexts that were excavated at Wari Kayán and at the Palpa valleys. As this sample is non-random and small, this study cannot to give a final answer to the possible reasons behind this practice in the Paracas realm, but it opens the discussion of this type of evidence, showing its potential and proposing a classification that allowed us to differentiate three groups of individuals: Those buried at the Peninsula and associated to Early Horizon textiles, those associated to Early Intermediate textiles and those coming from the southern valleys. / Uno de los aspectos que más llamó la atención de los arqueólogos desde las primeras exploraciones de la península de Paracas, a inicios del siglo XX, fueron las modificaciones craneales. Desde entonces hasta la fecha, se han realizado numerosas descripciones y clasificaciones, y se han propuesto diversas hipótesis referentes a las razones que estarían detrás de esta práctica cultural: estatus, género, origen, etnicidad, etc., elementos todos de la identidad. Sin embargo, todavía no se ha podido validar ninguna de estas hipótesis, porque no existe ningún estudio sistemático que haya clasificado las formas craneales y las haya relacionado con las características de los contextos de procedencia. En el marco del creciente interés por conocer la dinámica social y política de finales del Período Formativo en la costa sur del Perú, la identidad de las personasenterradas en los cementerios de la península de Paracas y su posible relación con poblaciones que habitaban los valles hacia el norte y hacia el sur, es un tema de discusión central, que ha sido abordado principalmente a partir del estudio de los objetos asociados a los enterramientos. En este contexto, el estudio de las modificaciones craneales adquiere relevancia, más aun considerando que los estudios genéticos no han logrado un nivel de resolución fino en el caso de Paracas. En este artículo, se estudia y clasifica las formas craneales de 38 individuos procedentes de 35 contextos funerarios paracas,excavados en el cementerio de Wari Kayán y en los valles de Palpa. Tratándose de una muestra pequeña y no aleatoria, este estudio no pretende dar una respuesta definitiva a las posibles razones detrás de esta práctica en el mundo Paracas.Por el contrario, el objetivo es abrir el camino para la inclusión de este tipo de estudios en la discusión, mostrando su potencialidad y presentando una propuesta de clasificación que nos ha permitido diferenciar tres grupos de individuos: aquellos enterrados en la península de Paracas que estaban asociados a textiles del Horizonte Temprano, los que estaban asociados a textiles del Intermedio Temprano y los que proceden de los valles sureños.

O estudo aborda as modificações corporais por meio de diversas técnicas, as possibilidades de vestuário que dão-se com as novas tecnologias e diferenciais nas modelagens básicas. As análises mostram como corpo e moda são simultâneos e ocorrem de acordo com a época em que estão inseridos. Tal estudo torna-se relevante por analisar corpo e moda no contemporâneo e como ambos estão em constante modificações. Para as análises, foram pesquisadas imagens diversas em que podemos verificar as transformações corporais e o motivo das mesmas, podendo ser por crenças religiosas, ou a fim de diferenciar-se ou enquadrar-se em determinados grupos, e imagens de moda em que podemos observar como as novas tecnologias são aplicadas a fim de obter um produto com aspectos inovadores, estes com propriedades desde as que podem auxiliar a medicina, como também aquelas com caráter apenas estético. Mostraremos como a moda pode obter determinados elementos a fim de termos um corpo híbrido nas passarelas e como, no contemporâneo, faz-se diferente até as apresentações de desfiles. / This essay deals with body modifications through many techniques, the possibilities of clothing which are obtained with new technologies and differentials in basic modelings. The analyses show how body and fashion are simultaneous and happen accordingly to the time in which they are inserted in. Such study becomes relevant by analysing body and fashion on contemporary days and how both of them are in constant changes. Several images were researched to enable the analyses, so that we can verify body transformations and the reasons why they happen ( be it for religious beliefs, for standing out from others or for taking part of a given group). We can observe in fashion images how new techniques are applied to get a product with innovative aspects which have properties that either may have only aesthetic character or can help medicine. We are going to show how fashion can get certain elements for us to have a hybrid body on stages and how even fashion shows are done differently nowadays.

Tissue engineering is an interdisciplinary field which aims to create substitutes of damaged tissues by combining cells with biomaterials. Cells are extremely sensitive to their microenvironment and so the cell response to biomaterials can be regulated by different extrinsic stimuli and alterations of biomaterial properties. Successful implant integration into the tissue can therefore be promoted by appropriate surface roughness, chemical composition, adhesion ligand density, as well as the availability of growth factors. This thesis mainly focuses on the development of orthopedic replacements and the improvement of the currently used blood vessel prostheses. Through the study of cell-biomaterial interactions, it was demonstrated that superimposed topography with features ranging from the nano to micro scale promotes cell spreading, proliferation, and the metabolic activity of osteoblast-like cells. Moreover, when comparing the chemical composition of biomaterials for orthopedic implants, higher osteoblast densities were observed on composites with 5-15 vol. % of calcium phosphate nanoparticles, while concentrations of 25 vol. % did not support cell proliferation. Cell viability, however, was not affected. In vivo, a more intensive formation of new bone tissue, was found on samples containing...