Disputation: William B. Reinar
PhD candidate William B. Reinar at the Department of Biosciences will be defending the thesis "Genomic short tandem repeats as modulators of gene expression and protein function" for the degree of PhD.
William B. Reinar
The disputation will also be live streamed using Zoom. The host of the session will moderate the technicalities while the chair of the defence will moderate the disputation.
Ex auditorio questions: The chair of the defence will invite the audience to ask ex auditorio questions either written or oral. This can be requested by clicking "Participants" followed by clicking "Raise hand".
The meeting opens for participation just before 1.15 PM, and closes for new participants approximately 15 minutes after the defense has begun.
Regulation of gene expression with emphasis on the role of transcription factors and chromatin
Main research findings
Repetitive DNA is an intrinsic, but puzzling feature of genomes. Unlike regular DNA sequences, mutations in repeats occur more frequently, and are driven by a distinct mechanism that leads to length alterations. The consequence is that in a given population, individuals may have repeats of completely different lengths – even near and within genes. The high rate of mutation in repeats could leave organisms better suited to adapt to rapid changes in the environment. However, the extent that length variation functionally impact genes, proteins and organism phenotypes is not clear.
In this PhD project, Reinar and colleagues investigated length variable repeats in bacterial strains of Neisseria and in wild specimens of the flowering plant Arabidopsis. In Neisseria length variation was shown to disrupt the function of a protein that adds a specific sugar to cell-surface proteins. Modelling and functional experiments in Arabidopsis revealed that length variable repeats affects the expression of genes. Moreover, it was discovered that repeats often encode protein sequences with special structural and biochemical properties. Experimental work on such protein regions suggested that specific repeat lengths was important for stress tolerance. In light of the natural environment of the Arabidopsis specimens, it was found that natural selection likely has shaped repeat length variation.