Whole-genome analysis of Fusarium graminearum insertional mutants identifies virulence associated genes and unmasks untagged chromosomal deletions

Systematic efforts are underway to characterise the gene functions in Fusarium graminearum. A relatively unbiased way to survey protein function is the generation of forward mutants. Here, we have adapted a high-throughput sequencing approach to characterise four insertional mutants in this species. The sequencing approach was able to identify a spectrum of unexpected molecular recombination events and large chromosomal deletions in several disease attenuated Fusarium (DAF) mutants. As a control to validate our high-throughput sequencing approach the strain TP11.1 (3002) affected in the topoisomerase I gene was used. Whole-genome sequencing of this strain confirmed the single site insertion event and identified no additional secondary genomic recombination events across its four chromosomes. However for the three reduced virulence mutants described in this study, DAF139 (2999), DAF140 (3000) and DAF141 (3001), more complex recombination events were observed likely caused during the transformation and insertion events.