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Showing result 1 - 5 of 63 swedish dissertations matching the above criteria.
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1. Aneuploidy compensatory mechanisms and genome-wide regulation of gene expression in Drosophila melanogaster
Abstract : Stimulation or repression of gene expression by genome-wide regulatory mechanisms is an important epigenetic regulatory function which can act to efficiently regulate larger regions or specific groups of genes, for example by compensating for loss or gain of chromosome copy numbers. In Drosophila melanogaster there are two known chromosome-wide regulatory systems; the MSL complex, which mediates dosage compensation of the single male X-chromosome and POF, which stimulates expression from the heterochromatic 4th chromosome. READ MORE
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2. Mitotic aberrations in mammalian cells
Abstract : Almost all cancer cells are aneuploid showing the wrong chromosome number and often with structural aberrations. The degree of aneuploidy correlates with an increase of the severity of the disease and tumour cells with chromosomal instability are more prone to acquire resistance to chemotherapy than other cells. READ MORE
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3. Hopeful monsters: The role of hybrids in adaptation : The impact of hybridisation and genetic diversity on adaptation to stressful and novel environments
Abstract : Adaptation to novel environments can only occur if natural selection has the raw material to act upon. But small, endangered populations are often genetically depleted, and the acquisition of beneficial de novo mutations often takes too long when population face quick and extreme environmental change. READ MORE
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4. Somatic Genetic Variation in Children: from Mosaicism to Cancer
Abstract : This thesis concerns various aspects of somatic mosaicism and genetic intratumor heterogeneity in childhood cancer.In paper I, I show that aneuploidy in itself does not lead to the level of chromosomal instability that is typically seen in malignant cells. This finding strongly argues against the so called autocatalytic theory of carcinogenesis. READ MORE
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5. Studies on in vitro fertilised human preembryos. Morphological and chromosomal aspects
Abstract : The success rate of in vitro fertilisation (IVF) has gradually increased due to basic research in preembryonic biology and the introduction of new methods, both technical and medical. However, further research is needed to establish which preembryos are developmentally most competent in order to be able to maintain the pregnancy rate while only a single preembryo is being transferred. READ MORE
