| Title: | Presence and functionality of mating type genes in the supposedly asexual filamentous fungus Aspergillus oryzae |
| Author(s): | Wada R; Maruyama J; Yamaguchi H; Yamamoto N; Wagu Y; Paoletti M; Archer DB; Dyer PS; Kitamoto K; |
| Address: | "Department of Biotechnology, The University of Tokyo, Tokyo, Japana; Bio'c Co., Ltd., Toyohashi, Japan" |
| ISSN/ISBN: | 1098-5336 (Electronic) 0099-2240 (Print) 0099-2240 (Linking) |
| Abstract: | "The potential for sexual reproduction in Aspergillus oryzae was assessed by investigating the presence and functionality of MAT genes. Previous genome studies had identified a MAT1-1 gene in the reference strain RIB40. We now report the existence of a complementary MAT1-2 gene and the sequencing of an idiomorphic region from A. oryzae strain AO6. This allowed the development of a PCR diagnostic assay, which detected isolates of the MAT1-1 and MAT1-2 genotypes among 180 strains assayed, including industrial tane-koji isolates. Strains used for sake and miso production showed a near-1:1 ratio of the MAT1-1 and MAT1-2 mating types, whereas strains used for soy sauce production showed a significant bias toward the MAT1-2 mating type. MAT1-1 and MAT1-2 isogenic strains were then created by genetic manipulation of the resident idiomorph, and gene expression was compared by DNA microarray and quantitative real-time PCR (qRT-PCR) methodologies under conditions in which MAT genes were expressed. Thirty-three genes were found to be upregulated more than 10-fold in either the MAT1-1 host strain or the MAT1-2 gene replacement strain relative to each other, showing that both the MAT1-1 and MAT1-2 genes functionally regulate gene expression in A. oryzae in a mating type-dependent manner, the first such report for a supposedly asexual fungus. MAT1-1 expression specifically upregulated an alpha-pheromone precursor gene, but the functions of most of the genes affected were unknown. The results are consistent with a heterothallic breeding system in A. oryzae, and prospects for the discovery of a sexual cycle are discussed" |
| Keywords: | "Amino Acid Sequence Aspergillus oryzae/genetics/growth & development/isolation & purification/*physiology DNA Primers/genetics DNA, Fungal/chemistry/genetics Food Microbiology Fungi/genetics/growth & development/physiology Gene Deletion Gene Expression Pr;" |
| Notes: | "MedlineWada, Ryuta Maruyama, Jun-Ichi Yamaguchi, Haruka Yamamoto, Nanase Wagu, Yutaka Paoletti, Mathieu Archer, David B Dyer, Paul S Kitamoto, Katsuhiko eng Biotechnology and Biological Sciences Research Council/United Kingdom Research Support, Non-U.S. Gov't 2012/02/14 Appl Environ Microbiol. 2012 Apr; 78(8):2819-29. doi: 10.1128/AEM.07034-11. Epub 2012 Feb 10" |
