Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 5 uppsatser.

No description available.

No description available.

The early gene region, EIA, of Adenovirus is responsible for two mRNAs that appear to be, along with their protein products, necessary for oncogenic transformation. The two proteins differ only in that the larger 289R protein has an extra internal sequence of 46 amino acids. This single difference must account for the functional differences between the two proteins. One function associated with this unique sequence is transactivation, the ability to transcriptionally activate the other early viral genes. In this thesis the construction and analysis of three in-frame deletion mutants are described. These three deletions, along with a fourth previously made, span the entire unique region. All three mutants had lost their transactivation ability, suggesting that the entire domain is necessary for transactivation. Transformation assays with these mutants also suggest that this function blocks transformation. Thus, the unique domain must encode another as yet unidentified function necessary for full transformation. Further evidence for another function in the unique domain comes from the differently reduced abilities of the mutants to grow on HeLa cells. Each mutant has differentially affected some function that is also necessary for lytic infection. / Thesis / Master of Science (MS)

A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg in partial fulfillment of the requirements for the degree of Master of Medicine in the Branch of Medical Genetic. Johannesburg, South Africa, 2012 / Fanconi anaemia (FA) is a genotypically and phenotypically heterogeneous genetic condition , characterized microscopically by chromosomal breakage and instability and usually inherited in an autosomal recessive manner. Affected individuals often present with a diverse variety of physical congenital abnormalities and most progress to haematological disease including bone marrow aplasia and myelodysplasia in early childhood. In South Africa, Black individuals with FA share a common causative founder deletion mutation in the Fanconi G gene (FANCG del) in 82% cases. They are thus an ideal patient cohort for a genotype-phenotype correlation study. Thirty Black patients, homozygous for FANCG del, were ascertained from haematology/oncology clinics in Johannesburg and Bloemfontein. They were subjected to a comprehensive clinical examination to a document their physical features. A concurrent review of each participant's hospital file allowed data to be collected regarding disease presentation and haematological progression . Significant growth abnormalities and a high frequency of skin of skin pigmentary anomalies were found in the research cohort. Although subtle, anomalies of the eye, ears, and hands were noted in a high frequency. The overall physical phenotype does not appear to be appreciably different from that described in other Fanconi anaemia cohorts; however, affected Black individuals may present with more severe haematological indices and have poorer outcome that FA individuals of heterogeneous genotype. Further, it would appear that haematological disease progression cannot be predicted by the presence of abnormalities.

Brain development and function rely on vascular features that ensure adequate supply of oxygen and nutrients from the blood stream. These features consist of a well-established vascular network, a functional blood-brain barrier, as well as cerebral blood flow regulation. Early life impairments in these features can lead to neurodevelopmental defects. Very few studies have considered the contribution of the brain vasculature to autism spectrum disorders (ASD). A recent postmortem study in young ASD brains suggested an impairment in angiogenesis, a process through which new vessels are formed. A possible link between ASD and altered cerebral perfusion has also been suggested by functional imaging studies. Yet, contribution of cerebrovascular deficits to ASD physiopathology remains elusive, hence a detailed analysis of these deficits is needed. ASD are viewed as neurodevelopmental conditions associated with genetic origins. Mutations identified as a possible cause for ASD include the common 16p11.2 deletion, which leads to the haploinsufficiency of approximately 30 highly-conserved genes. In this thesis, we are using a multidisciplinary approach in order to decipher the cerebrovascular underpinnings of ASD in a mouse model of the 16p11.2 deletion syndrome (16p11.2df/+ mice). We have identified functional and structural cerebrovascular deficits during postnatal development in constitutive 16p11.2df/+ mutants. In particular, 16p11.2df/+ mice display a significant decrease in microvascular branching and density in the cerebral cortex at P14 when compared to age-matched WT littermates. In addition, 16p11.2df/+ mice display a collection of functional abnormalities at P50 when compared to WT mice, such as altered neurovascular coupling in vivo and altered vascular reactivity ex vivo. Notably, we demonstrated a defective endothelium-dependent vasodilation in 16p11.2df/+ mice, while smooth muscle function is unaffected. Furthermore, we generated mice harboring the endothelial-specific 16p11.2 haploinsufficiency (Cdh5-Cretg/+;16p11.2flox/+) in order to dissect the endothelial contribution to ASD phenotypes. These mice underwent behavioral testing to assess whether they display 16p11.2 syndrome -related characteristics. We demonstrated that these conditional mutant mice show home cage hyperactivity in the beam break test, repetitive behaviors in the marble burying test, as well as motor coordination deficits in the rotarod test. Our findings thus establish endothelial cells as key contributors to the pathophysiology of the 16p11.2 deletion syndrome, and provide novel insight into how the cerebral endothelium fine-tunes brain maturation.

No description available.

No description available.

The intricacies and exceptions of high vowel deletion in Old English have been the subject of much debate in recent historical phonology. Traditional philological handbooks such as Campbell (1959) describe the process within the assumptions of the Neogrammarian tradition. As such, high vowel deletion has been described as a phonological process that removes historically high and synchronically unstressed vowels after a heavy syllable, or two light syllables. However, the descriptions in these handbooks also reveal that exceptions are common, and as per the Neogrammarian tradition, these are usually assumed to be the result of analogy. In contrast, recent studies have sought to account for the exceptions in a way that lends more explanatory power (e.g. Stratal Optimality accounts including Bermúdez-Otero 2005). Such accounts have shown that there is more to the exceptions than analogy, and that phonological rules, as their synchronic activity declines, can become entangled with other morphological and phonological conditioning, due to the high levels of surface opacity that causes them to become unlearnable. Many of the accounts of high vowel deletion have focused on the West Saxon of Alfred (Early WS) and Ælfric (late WS), and recent descriptions of high vowel deletion have largely focused upon the noun declensions (e.g. Bermúdez-Otero in prep) and the weak verb preterites (Minkova 2012). In this study, I focus in particular upon the behaviour of high vowel deletion in the strong and weak verbs; including the past participles and both the present and preterites. The selected data represent the Early West Saxon dialect and also the Late Northumbrian dialect found in the Lindisfarne Gospel gloss. Discussion of the process as found in nouns and adjectives will also be incorporated. The study has two larger aims: 1. To provide an analysis of syncope for newly collected data sets from Early West Saxon and Lindisfarne verbs, and 2. To contribute to the debate surrounding how to account for morphophonological interaction within inflexional paradigms. The data reveal evidence to show that high vowel deletion is indeed suffering from the demise of its original phonological conditions in the verbs. It is not argued however that full lexicalization has yet taken place throughout the verbs. Instead, the data present a range of degrees of morphologization, within which the original phonological conditions have become supplemented by additional morphological conditions. Additional phonological conditioning is also in evidence. The Lindisfarne strong past participles, it is argued, represent a morphological category within which weight-based syncope is synchronically blocked. The wider question of how and why morphological and phonological conditions come to be added to existing phonological processes is addressed, and I argue that such phenomena result from unsustainable levels of opacity in the grammar (Anderson 1989), and that a theoretical framework that allows for the interaction of phonology and morphology within the grammar is necessary. The Optimality Theoretic analyses proposed in this study have the benefit of accounting for instances of phonologization through constraint interaction. It is also argued that the ways in which morphological category determines a) the way in which a phonological condition applies, and b) whether it applies at all, is best analysed using cophonological analyses (Anttila 2002a etc.).

We demonstrate that hydrogen production can be increased by random mutagenesis using N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and that hydrogen production can be further increased in the chemically-mutagenized strain by targeted gene deletion and overexpression of genes related to formate metabolism. Chemical mutagenesis of Escherichia coli BW25113 hyaB hybC hycE::kan/pBS(Kan)-HycE to form strain 3/86 resulted in 109 +/- 0.5- fold more hydrogen; 3/86 lacks functional hydrogen uptake hydrogenases 1 and 2, has hydrogenproducing hydrogenase 3 inactivated from the chromosome, and has constitutively active hydrogenase 3 based on expression of the large subunit of hydrogenase 3 from a high copy number plasmid. Deleting fdoG, which encodes formate dehydrogenase O, (that diverts formate from hydrogen), from chemical mutagen 3/86 increased hydrogen production 188 +/- 0.50-fold (relative to the unmutagenized strain), and deletion of hycA, which encodes the repressor of formate hydrogen lyase (FHL), increased hydrogen production 232 +/- 0.50-fold. Deleting both fdoG and hycA increased hydrogen production 257 +/- 0.50-fold, and overexpressing fhlA along with the fdoG hycA mutations increased hydrogen 308 +/- 0.52-fold. Whole-transcriptome analysis of chemical mutagen 3/86 revealed 89 genes were induced and 31 genes were repressed. In an effort to identify chromosomal mutations in chemical mutagen 3/86, we performed comparative genome sequencing and identified two chromosomal loci with mutations in coding regions of ftnA and yebJ; however, neither gene was related to the increased hydrogen production as determined by the close vial (short) hydrogen assay. In addition, transposon mutagenesis, which is one of the most efficient strategies for creating random mutations in the genomic DNA, was performed in two different strains: E. coli BW25113 hyaB hybC hycA fdoG::kan/pCA24N-FhlA and E. coli MG1655 to identify beneficial mutations for hydrogen production. As a result of screening 461 E. coli BW25113 hyaB hybC hycA fdoG::kan/pCA24N-FhlA transformants and 1000 E. coli MG1655 transformants, three interesting mutations have been discovered in E. coli BW25113 hyaB hybC hycA fdoG::kan/pCA24N-FhlA transformants (gpsA, dipZ, glgP) and 1 beneficial mutation in E. coli MG1655 transformants (malT). When any of these genes gpsA, dipZ, or glgP is disrupted by Tn5 insertion, hydrogen production decreases 17, 3 and 8-fold, respectively. Additionally, when malT gene is disrupted by Tn5 insertion, hydrogen increases 3.4-fold.