Jonfinn Blix Knutsen

• Reinar, William Brynildsen; Greulich, Anne; Stø, Ida Myhrer; Knutsen, Jonfinn Mordekai Blix; Reitan, Trond & Tørresen, Ole K. [Show all 9 contributors for this article] (2023). Adaptive protein evolution through length variation of short tandem repeats in Arabidopsis. Science Advances. 9(12), p. 1–10. doi: 10.1126/sciadv.add6960. Full text in Research Archive Show summary

  Intrinsically disordered protein regions are of high importance for biotic and abiotic stress responses in plants. Tracts of identical amino acids accumulate in these regions and can vary in length over generations because of expansions and retractions of short tandem repeats at the genomic level. However, little attention has been paid to what extent length variation is shaped by natural selection. By environmental association analysis on 2514 length variable tracts in 770 whole-genome sequenced Arabidopsis thaliana, we show that length variation in glutamine and asparagine amino acid homopolymers, as well as in interaction hotspots, correlate with local bioclimatic habitat. We determined experimentally that the promoter activity of a light-stress gene depended on polyglutamine length variants in a disordered transcription factor. Our results show that length variations affect protein function and are likely adaptive. Length variants modulating protein function at a global genomic scale has implications for understanding protein evolution and eco-evolutionary biology.

• Stø, Ida Myhrer; Orr, Russell; Fooyontphanich, Kim; Jin, Xu; Knutsen, Jonfinn Mordekai Blix & Fischer, Urs [Show all 9 contributors for this article] (2015). Conservation of the abscission signaling peptide IDA during Angiosperm evolution: Withstanding genome duplications and gain and loss of the receptors HAE/HSL2. Frontiers in Plant Science. 6(OCTOBER). doi: 10.3389/fpls.2015.00931. Full text in Research Archive

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• Knutsen, Jonfinn Mordekai Blix (2017). Evolutionary and functional importance of simple repeats in 1135 Arabidopsis thaliana genomes. Full text in Research Archive Show summary

  The predominant view in biology has been that genetic variation caused by point mutations are the main source for evolutionary change. Yet, point mutations alone cannot account for the genetic variation necessary to deal with rapid environmental changes. Genes and promoters are enriched with the tandem repeats (TRs), which are sets of trinucleotides repeated in tandem and that can mutate 10 to 100 000 times faster than point mutations. A working hypothesis is that such sequences serves as evolutionary hotspots that facilitate adaptation by fine-tuning gene function. To test this hypothesis, we are surveying the repeat length variation present in genes from more than a thousand Arabidopsis individuals spread mainly across the northern hemisphere. We are exploring associations between repeat length variation and ecological clines, such as variation in temperature and precipitation. We will investigate the functional importance of the repeat lengths in a set of candidate genes, representing the variation observed in the wild, by introducing them into Arabidopsis and monitoring phenotypic changes at the molecular and morphological level. We will further expose the Arabidopsis plants to various physical and biological stress, and screen for phenotypic and genetic changes relating to trinucleotide TRs.

• Knutsen, Jonfinn Mordekai Blix (2017). Evolutionary and functional importance of simple repeats in eukaryotic genomes. Full text in Research Archive Show summary

  The predominant view in biology has been that genetic variation caused by point mutations are the main source for evolutionary change. Yet, point mutations alone cannot account for the genetic variation necessary to deal with rapid environmental changes. Genes and promoters are enriched with the tandem repeats (TRs), which are sets of trinucleotides repeated in tandem and that can mutate 10 to 100 000 times faster than point mutations. A working hypothesis is that such sequences serves as evolutionary hotspots that facilitate adaptation by fine-tuning gene function. To test this hypothesis, we are surveying the repeat length variation present in genes from more than a thousand Arabidopsis individuals spread mainly across the northern hemisphere. We are exploring associations between repeat length variation and ecological clines, such as variation in temperature and precipitation. We will investigate the functional importance of the repeat lengths in a set of candidate genes, representing the variation observed in the wild, by introducing them into Arabidopsis and monitoring phenotypic changes at the molecular and morphological level. We will further expose the Arabidopsis plants to various physical and biological stress, and screen for phenotypic and genetic changes relating to trinucleotide TRs.

View all works in NVA