This Genome Watch article highlights how giant fungal Starship transposons may facilitate the horizontal transfer of smaller transposable elements and adaptive genes across species, contributing to rapid genome evolution and phenotypic diversification.
A recent survey of 1,348 genomes across the fungal kingdom revealed the extent of HTT1. The authors inferred at least 5,906 independent events and estimated that horizontally derived TEs account for an average of 7.7%, and up to 67%, of fungal TE content. However, these transfers were not evenly distributed across fungal taxa. HTT was particularly common in the Mucoromycotina subphylum and in three classes within the Pezizomycotina subphylum: Sordariomycetes, Dothideomycetes and Leotiomycetes. Several TE groups were also more frequently transferred, including Tc1/mariner DNA transposons, Copia retrotransposons and Tad1 retrotransposons. Thus, both fungal lineage and TE type influence the distribution of HTT.