title: Cloning of a new bidirectionally selectable marker for Aspergillus strains.
abstract: Mutants that lack adenosine triphosphate sulfurylase (ATPsase; EC 2.7.7.4) are unable to use sulfate as sole source of sulfur and are also resistant to selenate. These mutants, denoted sC-, are readily obtained from any strain of Aspergillus niger or Aspergillus nidulans by the strong selection for selenate resistance. We have cloned the gene encoding ATPsase from A. nidulans by complementation of an sC mutant strain of A. nidulans with a gene library and show that plasmids containing this gene transform both A. niger and A. nidulans sC- strains, restoring their ability to grow on sulfate as sole sulfur source. The fact that strong selection for either sC+ or sC- can be applied provides a simple way of delivering genetically engineered constructs to any strain of A. niger including strains of industrial importance. In addition, this system is useful for gene replacements and other genomic DNA manipulations in Aspergillus species.
authors.affiliation: Allelix Biopharmaceuticals, Mississauga, Ontario, Canada.
authors.forename: F P
authors.initials: FP
authors.lastname: Buxton
authors.forename: D I
authors.initials: DI
authors.lastname: Gwynne
authors.forename: R W
authors.initials: RW
authors.lastname: Davies
mesh_terms: D001233:Aspergillus nidulans / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification; D001234:Aspergillus niger / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification; D015139:Blotting, Southern; D003001:Cloning, Molecular; D015723:Gene Library; D005800:Genes, Fungal; D005819:Genetic Markers; D009154:Mutation; D009713:Nucleotidyltransferases / Q000235:genetics*; D010957:Plasmids; D015183:Restriction Mapping; D064586:Selenic Acid; D012643:Selenium; D018036:Selenium Compounds; D013430:Sulfate Adenylyltransferase / Q000235:genetics*; D014170:Transformation, Genetic
chemical_list: D005819:Genetic Markers; D018036:Selenium Compounds; D009713:Nucleotidyltransferases; D013430:Sulfate Adenylyltransferase; D012643:Selenium; D064586:Selenic Acid