Identification of essential genes in the human fungal pathogen Aspergillus fumigatus by transposon mutagenesis.

Arnaud Firon, François Villalba, Roland Beffa, and Christophe d'Enfert .


The opportunistic pathogen Aspergillus fumigatus is the cause of the most frequent deadly airborne fungal infection in developed countries. In order to identify novel antifungal drug targets, we investigated the genome of A. fumigatus for genes that are necessary for efficient fungal growth. An artificial A. fumigatus diploid strain with one copy of an engineered impala160 transposon from Fusarium oxysporum integrated into its genome was used to generate a library of diploid strains by random in vivo transposon mutagenesis. Among 2,386 heterozygous diploid strains screened by parasexual genetics, 1.2% had a copy of the transposable element integrated into a locus essential for A. fumigatus growth. Comparison of genomic sequences flanking impala160 in these mutants with that of the genome of A. fumigatus allowed the characterization of 20 previously uncharacterized A. fumigatus genes. Among these, homologues of genes essential for Saccharomyces cerevisiae growth have been identified, as well as genes that do not share homologues in other fungal species. These results confirm that heterologous transposition using the transposable element impala is a powerful tool for functional genomics in ascomycota and pave the way for defining the complete set of essential genes in A. fumigatus, the first step towards a target-based development of new antifungal drugs.

abstract No: 

Fungal Genet. Newsl. 50 (Supl):abstract

Full conference title: 

22nd Fungal Genetics Conference
    • Fungal Genetics Conference 22nd (2001)