title: Cloning and analysis of the MAT1-2-1 gene from the traditional Chinese medicinal fungus Ophiocordyceps sinensis.
abstract: The entomopathogenic fungus Ophiocordyceps sinensis has been important in traditional Chinese medicine but has yet to be commercially cultivated. One bottleneck is the very low frequency of stromata formation from artificially infected moth larvae. The mating system of fungi is the determining factor for sexual reproduction, but mating-type genes of O. sinensis have not been previously investigated. In this study, the putative mating-type gene MAT1-2-1 within the MAT1-2 idiomorph was amplified by polymerase chain reaction (PCR) and was determined to consist of 859 nucleotides that encode 249 amino acids; genes within the MAT1-1 idiomorph, however, were not determined. The MAT1-2-1 gene contained the conserved high-mobility group (HMG) box, and MAT1-2-1 flanking sequences were subsequently obtained. Although no putative open reading frames of the MAT1-1 idiomorph were detected within the ca. 8-kb flanking sequences of MAT1-2-1, a putative DNA lyase gene (which is present next to both idiomorphs in some heterothallic fungi) was found ca. 3.0 kb downstream of MAT1-2-1. The intervening distance between MAT1-2-1 and the DNA lyase gene in O. sinensis is larger than that in Cordyceps militaris and Cordyceps takaomontana. In addition, O. sinensis showed low sequence similarities with C. militaris and C. takaomontana in both MAT1-2-1 and the DNA lyase gene. In the phylogenetic tree, different MAT1-2-1 haplotypes of O. sinensis clustered together with high bootstrap support. As a single-copy gene, MAT1-2-1 was detected in all examined O. sinensis isolates including tissue cultures and single-ascospore cultures. This report describes, for the first time, a mating-type gene of O. sinensis.
authors.affiliation: Institute of Applied Chemistry, Shanxi University, Taiyuan 030006, China.
authors.forename: Shu
authors.initials: S
authors.lastname: Zhang
authors.forename: Yong-Jie
authors.initials: YJ
authors.lastname: Zhang
authors.forename: Xing-Zhong
authors.initials: XZ
authors.lastname: Liu
authors.forename: Hua-An
authors.initials: HA
authors.lastname: Wen
authors.forename: Mu
authors.initials: M
authors.lastname: Wang
authors.forename: Dian-Sheng
authors.initials: DS
authors.lastname: Liu
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D049770:Genes, Mating Type, Fungal; D006999:Hypocreales / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny
chemical_list: D017931:DNA Primers; D005656:Fungal Proteins