Sökning: "chromosomes"

Visar resultat 16 - 20 av 326 avhandlingar innehållade ordet chromosomes.

1. 16. Splitting the sexes : The birth and senescence of sex chromosomes

   Författare :Aivars Cirulis; Evolutionär ekologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sex chromosome; Sexual conflict; Macrostomum lignano; Experimental evolution; Genomics of sex;

   Sammanfattning : The evolution of gonochorism from hermaphroditism can be gradual by increasing investment in one sex role while decreasing in the other, or rapid through the fixation of sex-role sterility mutations, eventually leading to the evolution of sex chromosomes. It is expected that the transition will involve a temporary state of gynodioecy or androdioecy as the mutations are not expected to take place at the same time. LÄS MER

3. 17. Advances in studying the role of genetic divergence and recombination in adaptation in non-model species

   Författare :Ramprasad Neethiraj; Christopher Wheat; Sören Nylin; Mathieu Joron; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Recombination; Genetic divergence; Lepidoptera; Genetic variation; Genetic diversity; Holocentric chromosomes; cis-regulatory variation; Allele-specific expression; populationsgenetik; Population Genetics;

   Sammanfattning : Understanding the role of genetic divergence and recombination in adaptation is crucial to understanding the evolutionary potential of species since they can directly affect the levels of genetic variation present within populations or species. Genetic variation in the functional parts of the genome such as exons or regulatory regions is the raw material for evolution, because natural selection can only operate on phenotypic variation already present in the population. LÄS MER

4. 18. Genomic and Peptidomic Characterization of the Developing Avian Brain

   Författare :Birger Scholz; Lennart Dencker; Eric Vilain; Uppsala universitet; []
   Nyckelord :Toxicology; Sex differentation; Sex determination; Sex chromosomes; Dosage Compensation; Genetic; Chickens; Coturnix; Gene Expression Profiling; Neuropeptides; Diencephalon; Toxikologi;

   Sammanfattning : Chicken and Japanese quail are commonly used models in developmental and sex specific neuroendocrine research. There is relatively little known about the mechanisms behind their sex specific brain development, especially regarding the impact of the sex chromosomes (male: ZZ, female ZW) in relation to gonadal hormones. LÄS MER

5. 19. Speciation genomics in Ficedula flycatchers

   Författare :Madeline Chase; Carina Mugal; Chris Jiggins; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; recombination; linked selection; selective sweeps; sex chromosomes; structural variation; birds; genome assembly; Biology with specialization in Evolutionary Genetics; Biologi med inriktning mot evolutionär genetik;

   Sammanfattning : Understanding what evolutionary processes have shaped patterns of genomic differentiation between species is a major aim of speciation genomics. However, disentangling the role of different processes that generate similar patterns remains a substantial challenge. LÄS MER

7. 20. Rates and patterns of molecular evolution in avian genomes

   Författare :Paulina Bolívar; Hans Ellegren; Carina F. Mugal; Mikkel Heide Schierup; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Molecular evolution; recombination; GC-biased gene conversion; Hill-Robertson interference; effective population size; dN dS; distribution of fitness effects; avian genomes; collared flycatcher; sex chromosomes; Biology with specialization in Evolutionary Genetics; Biologi med inriktning mot evolutionär genetik;

   Sammanfattning : Evolution is the change in inherited characteristics of a population through subsequent generations. The interplay of several evolutionary mechanisms determines the rate at which this change occurs. LÄS MER