Inaug.-diss.--Upsala. / "Quellen und literatur": p. [xi]-xix.

Cyanobacteria are globally widespread and ecologically highly significant photoautotrophic microorganisms, with diverse geno- and phenotypic characters unprecedented among prokaryotes. This phylum embraces representatives with an exclusive adaptability in highly specialized environments, from oligotrophic ocean waters to the interior of cells in symbiotic plants, the most extreme being the chloroplasts. Insertion sequences (ISs) are short (~1000 bp) mobile genetic elements prevalent in microbial genomes, potentially representing potent adaptive forces. In this thesis, hypotheses tested that ISs play significant roles in both reductive and adaptive evolution in physiologically versatile cyanobacteria, using two model systems. First, the genome of an obligate plant (Azolla) symbiont, the cyanobacterium ‘Nostoc azollae 0708’, was sequenced, which led to the discovery of a highly ‘eroding’ genome (5,48 Mbp), loaded with ISs covering 14% of the genome, a situation likely caused by the relaxed selection pressure within the plant. The ISs were located in close proximity to the extremely numerous pseudogenes identified, although genes with key functions in a symbiotic context escaped IS mediated erosion (e.g. nitrogen fixation and differentiation genes). Some ISs were shown to have transposed short distances within the genome (‘local hoping’), and to be likely causative agents in pseudogene formation, and thus pivotal actors in the reductive evolution discovered. To widen the scope of ISs further, additionally 66 phylogenetically diverse microorganisms with a variety of life styles (free-living, symbionts, pathogens) were examined in regards to ISs influence. The data verified their over-all importance in shaping microbial genomes. Finally, natural microbial populations in the Baltic Sea, a semi-enclosed geologically young (~10,000 years) brackish water body offering steep gradients in salinity and nutrient loads, were examined using metatranscriptomics and metagenomics. A large proportion of the metagenome was devoted to ISs and most importantly a large fraction of the metatranscriptome consisted of IS transcripts (~1%), which may be suggestive of a high IS activity. These phenomena were most apparent in cyanobacteria in central parts of the Baltic Sea. The presence of an especially rich abundance of ISs in brackish waters was further substantiated by their low frequency (&lt; 0.1%) in microbes of marine waters. Hence, ISs may facilitate both adaptations (short term) and adaptive evolution (long term) in microbes entering brackish water, otherwise unable to cross the distinct limnic-to-marine salinity-divide. Together, the data reveal high genomic loads of ISs in cyanobacteria subject to highly demanding conditions and stress the importance of locally migrating ISs (and pseudogenization) as important facilitators in adaptation and evolution, being a more rapid process than hitherto expected. The findings strongly support current theories stating a crucial role of ISs in shaping microbial genomes to render fitness. / <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 3: Manuscript.</p>

This report discusses the background of trigonometric sequences and series related to defining the sine and cosine functions. Proofs involving converging trigonometric sequences and series are presented using nontraditional methods. To conclude, an application of trigonometric sequences and series is shown. / text

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Nucleotide sequence data from several pea (Piswn sativum L.) seed storage protein genes was obtained. Of two legumin genes sequenced, one was shown to be a pseudogene, apparently once coding for a polypeptide belonging to the 'major' legumin class, whilst the other was shown to be a functional gene coding for a polypeptide of the 'minor' legumin class. Sequence data was also obtained for two vicilin genes. Complete sequencing of one revealed it to be truncated by sequence of unknown origin at its 3' end, whilst partial sequence for the other suggested the presence of a stop codon in the coding region. These findings implied that both vicilin genes are no longer functional. Additionally, various comparisons of nucleic acid and amino acid sequence data were made between these genes and also with other legume seed storage protein genes. Results showed these genes conform with the major structural features of eukaryotic genes, and also revealed the presence of potential tissue -specific regulatory elements in the 5' flanking regions of the genes. Dendrograms for legume 11S and 7S classes of globulin seed storage protein genes clearly supported the model theory of each class having arisen by successive duplications from a common ancestral gene.

Inaug.-diss.--Upsala. / "Quellen und literatur": p. [xi]-xix.

Thesis (doctoral)--Rheinische Friedrich-Wilhelms-Universität zu Bonn, 1917. / Vita. Includes bibliographical references.

Thesis (M. Sc.)--University of Alberta, 2009. / Title from pdf file main screen (viewed on Aug. 27, 2009). "A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Statistics, Department of Mathematical and Statistical Sciences, University of Alberta." Includes bibliographical references.