Suitability ofVaderfor Transposon-Mediated Mutagenesis inAspergillus niger

Abstract

ABSTRACTThe filamentous fungusAspergillus nigeris widely used in biotechnological applications. Strain CBS513.88 is known to harbor 21 copies of the nonautonomous transposonVader. Upon selection of chlorate-resistantA. nigercolonies, oneVadercopy was found integrated in thenirAgene. This copy was used for vector construction and development of a transposon-tagging method.Vadershowed an excision frequency of about 1 in 2.2 × 105conidiospores. A total of 95 of 97 colonies analyzed exhibited an excision event at the DNA level, andVaderfootprints were found. By employing thermal asymmetric interlaced (TAIL)-PCR, the reintegration sites of 21 independent excision events were determined. All reintegration events occurred within or very close to genes. Therefore, this method can be used for transposon mutagenesis inA. niger.