Genomic analyses reveal low mitochondrial and high nuclear diversity in the cyclosporin-producing fungus Tolypocladium inflatum
Genomic analyses reveal low mitochondrial and high nuclear diversity in the cyclosporin-producing fungus Tolypocladium inflatum
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DOI：
10.1007/s00253-017-8574-0
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发表时间：
2017-12-01
影响因子：
5
通讯作者：
Xu, Jianping
中科院分区：
文献类型：
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作者：
Zhang, Yong-Jie;Yang, Xiao-Qing;Xu, Jianping
在动物中，线粒体DNA通常被认为比核DNA进化得更快，而真菌中是否也是如此尚不清楚。在这里，我们注释的第一个完整的线粒体基因组（有丝分裂基因组）的环孢菌素生产真菌Tolypocladium inflatum和报告的全基因组序列变异之间的5个菌株来自遥远的分离地点。我们找到了T. inflatum具有最紧凑的真菌有丝分裂基因组;其25 kb DNA分子编码所有标准的真菌线粒体基因，并且仅含有一个内含子。转录分析验证了大多数保守基因的表达。我们发现了几个不常见的重复元件和基因转移的证据，从细胞核。系统发育分析证实了T. inflatum在真菌目肉座菌目，虽然有不确定性，其家庭水平的联系。比较基因组分析的五个菌株中确定了一个整体水平较低的种内变异的有丝分裂基因组比在核基因组，但是，核和线粒体基因组显示类似的隔离关系，不相关的地理来源，这些菌株。我们的研究为药用子囊菌T的进化提供了新的见解。膨胀
Mitochondrial DNA is generally regarded to evolve faster than nuclear DNA in animals, whereas if this is also true in fungi remains unclear. Herein, we annotate the first complete mitochondrial genome (mitogenome) of the cyclosporin-producing fungus Tolypocladium inflatum and report the genome-wide sequence variations among five isolates originating from distantly separated localities. We found that T. inflatum has among the most compact of fungal mitogenomes; its 25 kb DNA molecule encodes all standard fungal mitochondrial genes and harbors only one intron. Transcriptional analyses validated the expression of most conserved genes. We found several uncommon repetitive elements and evidence of gene transfer from the mitochondrion to the nucleus. Phylogenetic analyses confirmed the placement of T. inflatum in the fungal order Hypocreales although there was uncertainty on its family-level affiliation. Comparative genomic analyses among the five isolates identified an overall lower level of intraspecific variation in mitogenomes than in nuclear genomes; however, both the nuclear and mitochondrial genomes revealed similar isolate relationships, not correlating with geographic sources of these isolates. Our study shed new insights into the evolution of the medicinally important ascomycete T. inflatum.