Honors Program


Document Type


Date of this Version



Johnson, C. 2023. Utilizing MitoTALENs to Investigate Large Repeats in the Arabidopsis thaliana Mitochondrial Genome. Undergraduate Honors Thesis. University of Nebraska-Lincoln.


Copyright Cambelle Johnson 2023


Mitochondria are a silly place to store the genetic code. In spite of the ever-present threat of oxidative DNA damage, plant mitochondrial genomes are expansive in size and include noncoding repeat sequences, a small number of which are greater than 1kilobase (kb), known hereafter as “large repeats” (LR). This theme of one or more large repeat pairs is shared across most flowering plants, lending to the belief that they somehow contribute to the plant’s fitness. These repeats exhibit high rates of rearrangement and recombination. Studying repeats in vivo could have large scale implications in hybrid crop production enhancement including eliminating the process of emasculation. MitoTALENs are a tool that facilitates the targeted cutting of a specific sequence in the mitochondrial genome, bypassing the natural barriers to in vivo deletion. This experiment utilizes mitoTALENs to remove large repeats for the first time in vivo from Arabidopsis thaliana’s mitochondrial genome and observe the genomic and phenotypic effects of their absence. The downstream effects of mitoTALEN-mediated deletions will inform on not only the significance of large repeats and their connections to flowering plant fitness and reproduction, but perhaps their evolutionary origins in the mitochondrial genome.