Sökning: "Gene Frequency"

Visar resultat 11 - 15 av 383 avhandlingar innehållade orden Gene Frequency.

  1. 11. Causes of Substitution Frequency Variation in Pathogenic Bacteria

    Författare :Wagied Davids; Siv Andersson; Otto Berg; Bengt Persson; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biology; Comparative genomics; Molecular evolution; Bioinformatics; Human pathogens; Rickettsia; Helicobacter pylori; Biologi; Biology; Biologi;

    Sammanfattning : Estimating substitution frequencies at sites that influence (Ka) and do not influence (Ks) the amino acid sequence is important for understanding the dynamics of molecular sequence evolution and the selective pressures that have shaped genetic variation. The aim of this work was to gain a deeper understanding of the driving forces of substitution frequency variation in human pathogens. LÄS MER

  3. 12. LXR regulation of hepatic gene expression and pituitary dependent hormones

    Författare :Pia Kotokorpi; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :Liver X receptor; growth hormone; gene regulation; metabolism; hepatocyte; hepatic steatosis; species differences;

    Sammanfattning : The liver X receptors (LXRs) are ligand activated transcription factors involved in the regulation of metabolic genes. LXRs are considered potential drug targets to treat metabolic disorders, however, unwanted side effects, as revealed from rodent studies, include increased lipogenesis in the liver and increased plasma triglyceride levels. LÄS MER

  4. 13. Dynamics and Mechanisms of Adaptive Evolution in Bacteria

    Författare :Song Sun; Dan Andersson; Diarmaid Hughes; Josep Casadesús; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; adaptive evolution; mutation; genome rearrangements; antibiotic resistance; gene amplification; genome reduction; directed evolution; Biologi med inriktning mot mikrobiologi; Biology with specialization in Microbiology;

    Sammanfattning : Determining the properties of mutations is fundamental to understanding the mechanisms of adaptive evolution. The major goal of this thesis is to investigate the mechanisms of bacterial adaptation to new environments using experimental evolution. LÄS MER

  5. 14. Tracing selection and adaptation along an environmental gradient in Populus tremula

    Författare :David Hall; Pär Ingvarsson; Thomas Bataillon; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Local adaptation; Selection; genetic differentiation; QST; FST; Association study; frequency spectra; recurrent hitchhiking; selective sweep; Tree; Populus; natural selection; quantitative genetics; Terrestrial ecology; Terrestrisk ekologi; Population Biology; populationsbiologi; genetik; Genetics;

    Sammanfattning : The distribution of the expressed genotype is moved around in the population over time byevolution. Natural selection is one of the forces that act on the phenotype to change the patterns ofnucleotide variation underlying those distributions. LÄS MER

  7. 15. Development of Transgenic Potatoes to Attain Novel Starch Qualities

    Författare :Mariette Andersson; Tillämpad biokemi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Livsmedelsteknik; Food and drink technology; Biokemisk teknik; Biochemical technology; StGH; starch yield; RNAi; antisense; gene silencing; ahas; potato transformation; sbe2; sbe1; gbss; amylopectin; amylose; Starch; potato;

    Sammanfattning : Starch is a plant-derived polysaccharide with many uses in different food and non-food applications. In this thesis, the production of two novel potato starch qualities, amylopectin and high-amylose, and the modifications and the characteristics of the produced plants and starches are described. LÄS MER