title: Genome editing in Ustilago maydis using the CRISPR-Cas system.
abstract: This communication describes the establishment of the type II bacterial CRISPR-Cas9 system to efficiently disrupt target genes in the fungal maize pathogen Ustilago maydis. A single step transformation of a self-replicating plasmid constitutively expressing the U. maydis codon-optimized cas9 gene and a suitable sgRNA under control of the U. maydis U6 snRNA promoter was sufficient to induce genome editing. On average 70% of the progeny of a single transformant were disrupted within the respective b gene. Without selection the self-replicating plasmid was lost rapidly allowing transient expression of the CRISPR-Cas9 system to minimize potential long-term negative effects of Cas9. This technology will be an important advance for the simultaneous disruption of functionally redundant genes and gene families to investigate their contribution to virulence of U. maydis.
authors.affiliation: Max Planck Institute for Terrestrial Microbiology, Department of Organismic Interactions, Karl-von-Frisch-Strasse 10, 35043 Marburg, Germany.
authors.forename: Mariana
authors.initials: M
authors.lastname: Schuster
authors.affiliation: Max Planck Institute for Terrestrial Microbiology, Department of Organismic Interactions, Karl-von-Frisch-Strasse 10, 35043 Marburg, Germany.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Schweizer
authors.affiliation: Max Planck Institute for Terrestrial Microbiology, Department of Organismic Interactions, Karl-von-Frisch-Strasse 10, 35043 Marburg, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Reissmann
authors.affiliation: Max Planck Institute for Terrestrial Microbiology, Department of Organismic Interactions, Karl-von-Frisch-Strasse 10, 35043 Marburg, Germany. Electronic address: kahmann@mpi-marburg.mpg.de.
authors.forename: Regine
authors.initials: R
authors.lastname: Kahmann
mesh_terms: D064113:CRISPR-Cas Systems; D000072669:Gene Editing; D005800:Genes, Fungal; D054884:Host-Pathogen Interactions; D010957:Plasmids; D059386:Reverse Genetics / Q000379:methods; D014588:Ustilago / Q000235:genetics*; D014774:Virulence / Q000235:genetics; D003313:Zea mays / Q000382:microbiology
keywords: Biotrophic fungus; Cas9; Plant pathogen; Reverse genetics; Ustilago maydis