Inactivation of ku80 in the mushroom-forming fungus Schizophyllum commune increases the relative incidence of homologous recombination

Abstract

Schizophyllum commune is the only mushroom-forming fungus in which targeted gene deletions by homologous recombination have been reported. However, these deletions occur with a low frequency. To overcome this, the ku80 gene of S. commune was deleted. This gene is involved in the nonhomologous end-joining system for DNA repair. The Deltaku80 strain was not affected in growth and development. However, the transformation efficiency was reduced up to 100-fold. This was accompanied by a strong increase in the relative number of transformants with a homologous integration of a knockout construct. Genes sc15, jmj3 and pri2 were deleted in the Deltaku80 strain. In total, seven out of 10 transformants showed a gene deletion. This frequency will facilitate a systematic analysis of gene function in S. commune.

Predominance of a Versatile-Peroxidase-Encoding Gene, mnp4 , as Demonstrated by Gene Replacement via a Gene Targeting System for Pleurotus ostreatus

“…The NHEJ pathway has been successfully impaired in a large number of filamentous fungi via disruption of either ku70 or ku80 homologs. To date, ku disruption strains from more than 20 different species (a majority of which are Ascomycetes) have been generated, showing significantly increased homologous recombination frequency (between 50% and 100%) (4,20,(24)(25)(26)38).…”

Mating-type genes and hyphal fusions in filamentous basidiomycetes

“…This can only be achieved by cell and molecular biological research applying efficient gene deletion procedures (de Jong et al, 2010;Ohm et al, 2010b;Nakazawa et al, 2011b), localization of nuclei (Fig 4) and the proteins from different regulation pathways in living hyphae as well as applying different biochemical methods to reveal the protein interactions at complexes associated with hyphal fusions and with signaling pathways regulated by A and B mating type genes in filamentous basidiomycetes.…”

Efficient gene targeting in ΔCc.ku70 or ΔCc.lig4 mutants of the agaricomycete Coprinopsis cinerea

“…It may be that the disruption of Cc.ku70 affects fruiting in C. cinerea. In another agaricomycete, S. commune, the defect of a component (Ku80) involved in the NHEJ pathway does not affect fruiting (de Jong et al, 2010).…”

“…In filamentous fungi, it was first found in Neurospora crassa that the disruption of a NHEJ-related gene (a homolog of human ku70, ku80 or lig4) results in great increase of the frequency of gene targeting by homologous integration (Ninomiya et al, 2004;Ishibashi et al, 2006). Following the reports in N. crassa, high-frequency gene targeting systems were established using the same strategy in various fungi (for a review, see Kück and Hoff, 2010), including several Aspergillus species (da Silva Ferreira et al, 2006;Nayak et al, 2006;Takahashi et al, 2006;Meyer et al, 2007), Hypocrea jecorina (Guantao et al, 2009), Penicillium chrysogenum (Snoek et al, 2009), Magnaporthe grisea (Villalba et al, 2008), Cryptococcus neoformans (Goins et al, 2006), and Schizophyllum commune (de Jong et al, 2010).…”