Transposons in biotechnologically relevant strains of Aspergillus niger and Penicillium chrysogenum

In the past 15 years, many class I and class II transposons were identified in filamentous fungi. However, little is known about the influence of transposons during industrial strain development. The availability of the complete genome sequences of the industrially relevant fungi Aspergillus niger and Penicillium chrysogenum has enabled an analysis of transposons present in these two fungi. Here, a compilation of the transposon-like sequences identified is provided. We investigated a yet undescribed A. niger retrotransposon, ANiTa1, as well as two P. chrysogenum transposons (PeTra1 and PeTra2), which are the first P. chrysogenum transposons ever described, in more detail. Analysis of the genomic distribution of selected transposable elements in five strains of A. niger and seven strains of P. chrysogenum revealed the transposon distribution to be virtually identical. However, one element, Vader—previously published—from A. niger, showed strain-specific differences in transposon distribution, suggesting transposition activity during classical strain improvement programs.