title: Complete mitochondrial genome of the medicinal fungus Ophiocordyceps sinensis.
abstract: As part of a genome sequencing project for Ophiocordyceps sinensis, strain 1229, a complete mitochondrial (mt) genome was assembled as a single circular dsDNA of 157,510 bp, one of the largest reported for fungi. Conserved genes including the large and small rRNA subunits, 27 tRNA and 15 protein-coding genes, were identified. In addition, 58 non-conserved open reading frames (ncORFs) in the intergenic and intronic regions were also identified. Transcription analyses using RNA-Seq validated the expression of most conserved genes and ncORFs. Fifty-two introns (groups I and II) were found within conserved genes, accounting for 68.5% of the genome. Thirty-two homing endonucleases (HEs) with motif patterns LAGLIDADG (21) and GIY-YIG (11) were identified in group I introns. The ncORFs found in group II introns mostly encoded reverse transcriptases (RTs). As in other hypocrealean fungi, gene contents and order were found to be conserved in the mt genome of O. sinensis, but the genome size was enlarged by longer intergenic regions and numerous introns. Intergenic and intronic regions were composed of abundant repetitive sequences usually associated with mobile elements. It is likely that intronic ncORFs, which encode RTs and HEs, may have contributed to the enlarged mt genome of O. sinensis.
authors.affiliation: State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.|College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.|University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Xiao-Di
authors.initials: XD
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.|University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Rui-Heng
authors.initials: RH
authors.lastname: Yang
authors.affiliation: School of Environmental Sciences, University of Guelph, Ontario, N1G 2W1, Canada.
authors.forename: Tom
authors.initials: T
authors.lastname: Hsiang
authors.affiliation: State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.|University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Wang
authors.affiliation: Nextomics Biosciences Co., Ltd., Wuhan 430075, China.
authors.forename: De-Quan
authors.initials: DQ
authors.lastname: Liang
authors.affiliation: Nextomics Biosciences Co., Ltd., Wuhan 430075, China.
authors.forename: Fan
authors.initials: F
authors.lastname: Liang
authors.affiliation: Nextomics Biosciences Co., Ltd., Wuhan 430075, China.
authors.forename: De-Ming
authors.initials: DM
authors.lastname: Cao
authors.affiliation: Nextomics Biosciences Co., Ltd., Wuhan 430075, China.
authors.forename: Fan
authors.initials: F
authors.lastname: Zhou
authors.affiliation: Nextomics Biosciences Co., Ltd., Wuhan 430075, China.
authors.forename: Ge
authors.initials: G
authors.lastname: Wen
authors.affiliation: State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Yi-Jian
authors.initials: YJ
authors.lastname: Yao
mesh_terms: D001203:Ascomycota / Q000145:classification / Q000235:genetics*; D001482:Base Composition; D017124:Conserved Sequence; D021901:DNA, Intergenic; D023061:Gene Order; D016681:Genome, Fungal; D054629:Genome, Mitochondrial; D023281:Genomics; D007438:Introns; D016366:Open Reading Frames; D010802:Phylogeny; D012091:Repetitive Sequences, Nucleic Acid; D014158:Transcription, Genetic
chemical_list: D021901:DNA, Intergenic