title: Establishment of a new method to quantitatively evaluate hyphal fusion ability in Aspergillus oryzae.
abstract: Hyphal fusion is involved in the formation of an interconnected colony in filamentous fungi, and it is the first process in sexual/parasexual reproduction. However, it was difficult to evaluate hyphal fusion efficiency due to the low frequency in Aspergillus oryzae in spite of its industrial significance. Here, we established a method to quantitatively evaluate the hyphal fusion ability of A. oryzae with mixed culture of two different auxotrophic strains, where the ratio of heterokaryotic conidia growing without the auxotrophic requirements reflects the hyphal fusion efficiency. By employing this method, it was demonstrated that AoSO and AoFus3 are required for hyphal fusion, and that hyphal fusion efficiency of A. oryzae was increased by depleting nitrogen source, including large amounts of carbon source, and adjusting pH to 7.0.
authors.affiliation: a Department of Biotechnology , The University of Tokyo , Tokyo , Japan.
authors.forename: Wakako
authors.initials: W
authors.lastname: Tsukasaki
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Maruyama
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Kitamoto
mesh_terms: D001236:Aspergillus oryzae / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D002244:Carbon / Q000494:pharmacology; D046508:Culture Techniques / Q000379:methods*; D005656:Fungal Proteins / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D025301:Hyphae / Q000187:drug effects / Q000502:physiology*; D009584:Nitrogen / Q000494:pharmacology; D012100:Reproduction, Asexual / Q000187:drug effects
chemical_list: D005656:Fungal Proteins; D002244:Carbon; D009584:Nitrogen
keywords: Aspergillus oryzae; heterokaryon; hyphal fusion