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- Plants are under constant attack from a diverse set of both old and newly emerging pathogens that cause disease. Diseases of crops take away an estimated 20-40% of our crop yields every year [1], leading to serious food shortages that have devastating impacts on the health and well-being of over 800 million people estimated to be food insecure [2]. To prevent yield losses, we need to understand what tools pathogens use to cause disease; these tools are referred to as "virulence" genes. We also need to understand how pathogens that infect the same crop might share these tools with each other. The sharing of virulence genes between unrelated pathogens is known as "horizontal gene transfer" (HGT). HGT between pathogenic species is dangerous because it can lead to rapid changes in speed at which a pathogen damages the plant, driving much larger yield losses. HGT is also known to lead to the rapid spread of antibiotic resistance genes. While we have a good understanding of the ways in which bacterial pathogens use HGT to exchange virulence/antibiotic resistance genes, our knowledge of how fungal pathogens do this is very limited. This lack of knowledge is of grave concern as fungal diseases are already difficult to control, and the growing negative impact of fungi is a risk to both human and plant health. I have recently discovered that a virulence gene, called ToxA, has jumped via HGT between three fungal wheat pathogens inside of a giant transposon. Transposons, also known as "jumping genes", contain genetic machinery that enables them to move around a genome. The finding of ToxA in a transposon is important because this protein alone can cause serious disease symptoms on wheat, and if transferred to a new fungal species a new disease could emerge. These giant transposons belong to a new transposon group called "Starships". They are unusual because of their large size, often exceeding some small fungal chromosomes, because they carry many genes. I hypothesize that the extra genes that Starships carry enable them to move themselves between different fungal species. The goal of this Fellowship is to uncover how Starships jump both within a genome inside one species and also between different fungal species, with the intention to use this knowledge to then predict which fungal species Starships can hop into. Starships have only been described within the last year making them very novel and exciting new components of fungal biology. I aim to be one of the first groups in the world to understand how these Starships work and how they might threaten our global crop yields by moving dangerous genes between different fungal pathogens. In the long-term my aim is to adapt these transposons for our own use in biotechnology by programming them to capture genetic material of our choice and moving this material into a suitable host for further study. Adapting natural systems, such as Starships, for our own use in bioengineering has led to several monumental steps forward in human health, sustainable production of biomaterials and medicines. [1] https://www.gov.uk/government/statistics/united-kingdom-food-security-report-2021 [2] https://www.fao.org/3/cc0639en/online/cc0639en.html