Sökning: "Biologiska institutionen"

Visar resultat 1 - 5 av 2334 avhandlingar innehållade orden Biologiska institutionen.

  1. 1. Genomic and morphological diversity of marine planktonic diatom-diazotroph associations : a continuum of integration and diversification through geological time

    Författare :Andrea Caputo; Rachel Ann Foster; Monika Quinones Winder; Ramon Massana; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; phytoplankton; diatoms; cyanobacteria; diazotrophs; symbiosis; evolution; phylogenetics; confocal microscopy; qPCR; CARD-FISH; tropics; sub-tropics; marin ekologi; Marine Ecology;

    Sammanfattning : Symbioses between eukaryotes and nitrogen (N2)-fixing cyanobacteria (or diazotrophs) are quite common in the plankton community. A few genera of diatoms (Bacillariophyceae) such as Rhizosolenia, Hemiaulus and Chaetoceros are well known to form symbioses with the heterocystous diazotrophic cyanobacteria Richelia intracellularis and Calothrix rhizosoleniae. LÄS MER

  3. 2. Reproductive physiology of the female three-spined stickleback, Gasterosteus aculeatus

    Författare :Chrysoula Roufidou; Bertil Borg; Geir Lasse Taranger; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; overripening of eggs; spawning cycle; brain-pituitary-gonad BPG axis; vitellogenin; ovarian fluid; sex steroids; reproduction; three-spined stickleback; Gasterosteus aculeatus; fish; Functional Zoomorphology; funktionell zoomorfologi;

    Sammanfattning : Reproduction in vertebrates, including fishes, is under control of the brain-pituitary-gonad (BPG) axis. The female three-spined stickleback, Gasterosteus aculeatus, produces egg clutches at intervals of a few days and spawns them in a nest built by male. LÄS MER

  4. 3. Molecular Evolution of the Vertebrate Genome

    Författare :Kiwoong Nam; Hans Ellegren; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP;

    Sammanfattning : In this thesis, I studied molecular evolution of the vertebrate genome, focusing on sex chromosomes, protein coding genes, and genome size variation. The evolutionary history of avian sex chromosomes was analyzed by comparing substitution rate among 12 gametologous gene pairs on the Z and W chromosomes. LÄS MER

  5. 4. Evolutionary Dynamics of Mutation and Gene Transfer in Bacteria

    Författare :Peter A Lind; Dan I Andersson; J. Arjan G. M. de Visser; Uppsala universitet; []
    Nyckelord :MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; fitness cost; bacterial evolution; gene amplification; mutational biases; GC content; synonymous substitutions; horizontal gene transfer; experimental evolution; Bacteriology; Bakteriologi; Microbiology; Mikrobiologi; Genetics; Genetik; Biology; Biologi; Mikrobiologi; Microbiology;

    Sammanfattning : The study of bacterial evolution is fundamental for addressing current problems of antibiotic resistance and emerging infectious diseases and lays a solid foundation for successful and rational design in biotechnology and synthetic biology. The main aim of this thesis is to test evolutionary hypotheses, largely based on theoretical considerations and sequence analysis, by designing scenarios in a laboratory setting to obtain experimental data. LÄS MER

  7. 5. Studies of Budding Yeast Transcription Factors Acting Downstream of Nutrient Signaling Pathways

    Författare :Niklas Nordberg; Hans Ronne; Anders Blomberg; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; Budding yeast; nutrient signaling; glucose repression; aging; caloric restriction; JmjC; histone demethylation; Mig1; Mig2; Mig3; Gis1; Rph1; Molekylär genetik; Molecular Genetics;

    Sammanfattning : Being able to respond to extracellular cues such as nutrients and growth factors is of vital importance to all living cells. Pathways have therefore evolved which can sense the extracellular status, transmit a signal through the cell and affect gene expression, which ultimately enables adaptation. LÄS MER