show Abstracthide AbstractDuring murine infection, transposon mutagenesis is a significant driver of spontaneous mutations in the human fungal pathogen Cryptococcus neoformans var. neoformans. We have shown that mutations caused by transposable element (TE) insertion into reporter genes were dramatically elevated at high temperature (37 versus 30 degrees Celsius) in vitro, suggesting that heat stress stimulates TE mobility. Here, to explore the genome-wide impact of TE mobilization, we generated transposon accumulation lines (TA lines) by in vitro passage of C. neoformans var. neoformans strain XL280 for multiple generations at 30 degrees Celsius or at the host-relevant temperature of 37 degrees Celsius. Utilizing whole genome sequencing, we identified native copies of mobile TEs and mapped multiple de novo insertions in these TA lines.