title: Minos as a novel Tc1/mariner-type transposable element for functional genomic analysis in Aspergillus nidulans.
abstract: Transposons constitute powerful genetic tools for gene inactivation, exon or promoter trapping and genome analyses. The Minos element from Drosophila hydei, a Tc1/mariner-like transposon, has proved as a very efficient tool for heterologous transposition in several metazoa. In filamentous fungi, only a handful of fungal-specific transposable elements have been exploited as genetic tools, with the impala Tc1/mariner element from Fusarium oxysporum being the most successful. Here, we developed a two-component transposition system to manipulate Minos transposition in Aspergillus nidulans (AnMinos). Our system allows direct selection of transposition events based on re-activation of niaD, a gene necessary for growth on nitrate as a nitrogen source. On average, among 10(8) conidiospores, we obtain up to ∼0.8×10(2) transposition events leading to the expected revertant phenotype (niaD(+)), while ∼16% of excision events lead to AnMinos loss. Characterized excision footprints consisted of the four terminal bases of the transposon flanked by the TA target duplication and led to no major DNA rearrangements. AnMinos transposition depends on the presence of its homologous transposase. Its frequency was not significantly affected by temperature, UV irradiation or the transcription status of the original integration locus (niaD). Importantly, transposition is dependent on nkuA, encoding an enzyme essential for non-homologous end joining of DNA in double-strand break repair. AnMinos proved to be an efficient tool for functional analysis as it seems to transpose in different genomic loci positions in all chromosomes, including a high proportion of integration events within or close to genes. We have used Minos to obtain morphological and toxic analogue resistant mutants. Interestingly, among morphological mutants some seem to be due to Minos-elicited over-expression of specific genes, rather than gene inactivation.
authors.affiliation: Faculty of Biology, University of Athens, Panepistimioupolis, Athens 15784, Greece.
authors.forename: Minoas
authors.initials: M
authors.lastname: Evangelinos
authors.affiliation: Faculty of Biology, University of Athens, Panepistimioupolis, Athens 15784, Greece.
authors.forename: Gerasimos
authors.initials: G
authors.lastname: Anagnostopoulos
authors.affiliation: Faculty of Biology, University of Athens, Panepistimioupolis, Athens 15784, Greece.
authors.forename: Iliana
authors.initials: I
authors.lastname: Karvela-Kalogeraki
authors.affiliation: Faculty of Biology, University of Athens, Panepistimioupolis, Athens 15784, Greece.
authors.forename: Panagiota M
authors.initials: PM
authors.lastname: Stathopoulou
authors.affiliation: Department of Microbiology, Imperial College London, London SW7 2AZ, United Kingdom; Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Bâtiment 400, 91405 Orsay Cedex, France.
authors.forename: Claudio
authors.initials: C
authors.lastname: Scazzocchio
authors.affiliation: Faculty of Biology, University of Athens, Panepistimioupolis, Athens 15784, Greece. Electronic address: diallina@biol.uoa.gr.
authors.forename: George
authors.initials: G
authors.lastname: Diallinas
mesh_terms: D000818:Animals; D001233:Aspergillus nidulans / Q000235:genetics*; D004251:DNA Transposable Elements; D004330:Drosophila / Q000235:genetics; D005827:Genetics, Microbial / Q000379:methods*; D023281:Genomics / Q000379:methods*; D016254:Mutagenesis, Insertional / Q000379:methods*
chemical_list: D004251:DNA Transposable Elements
keywords: Class II transposons; Filamentous fungi; Gene-tagging; Genetics