Structural analysis of the mitochondrial genome from the higher basidiomycete, Pleurotus ostreatus

高等担子菌的线粒体基因组（mt-genomes）关于基因组整体结构或基因结构和功能的分子遗传信息非常少。本研究的目的是评估线粒体基因组的整体结构的高等担子菌Pleoporostreatus和澄清的线粒体DNA限制性片段长度多态性（RFLP）的基础，在自然种群的这种真菌。于是，我确定了两种类型的完整核苷酸序列（菌株编号：5 17型和-286型）的线粒体基因组。这两个线粒体基因组是71,948和72,466个碱基对的环状分子，我观察到它们非常富含A + T（约73%）。通过BLAST和tRNA-scan程序对517型菌株线粒体基因组进行基因搜索，共鉴定出55个可能的基因。这些基因包括两种核糖体RNA的基因、26种转运RNA（tRNA）的基因和14种功能已知蛋白质的开放阅读框架（ORF）， ...更多信息 13个ORF被预测为可能的基因，不包括内含子ORF。糙皮侧耳mt-基因组的基因含量与已报道的其他真菌mt-基因组的基因含量基本相同。在mt-基因组中编码的tRNA基因的数量不足以支持线粒体蛋白质的合成，这表明mt-基因组中检测不到的tRNA基因可能是核编码的，并且是从细胞质输入的。比较两个线粒体基因组结构，没有发现差异之间的两个线粒体基因组分析的基因内容，基因顺序和方向的翻译每个基因。然而，在比较两个mt-基因组之间的序列差异时，发现多个小尺寸插入/缺失和点突变主要发生在基因的间隔区，其中一些产生了新的限制性位点。此外，插入/缺失大于1 kb的大片段也被发现在基因的间隔区和属内区域，其中有不同的内含子序列。这特别表明，每个线粒体基因组所含内含子序列的差异是在两者中观察到的RFLP产生的主要基础。少

The mitochondrial genomes (mt-genomes) of the higher basidiomycetes have very little molecular genetic information regarding overall genome structure or gene structure and function. The aim of this study is to evaluate the overall structure of mt-genomes of the higher basidiomycete Pleurotus ostreatus and to clarify the basis for mitochondrial DNA restriction fragment length polymorphism (RFLP) in natural populations of this fungus. I thereupon determined the complete nucleotide sequence of two types (strain no.-5 17 type and -286 type) mt-genomes of this fungus. The two mt-genomes are 71,948 and 72,466 base pairs circular molecules and I observed that they are very A + T rich (about 73%). By searching for genes in the strain no. 517 type mt-genome using the programs BLAST and tRNA-scan, a total of 55 possible genes were identified. These included genes for two species of ribosomal RNA, 26 genes of transfer RNA (tRNA) and 14 open reading frames(ORFs) for functionally known proteins and … More 13 ORFs predicted as possible genes, excluding intronic ORFs. The gene content of P.ostreatus mt- genome is considered to be virtually the same as that of the other fungal mt- genomes that have been reported. The number of tRNA genes encoded in the mt- genome was not sufficient to support the synthesis of mitochondrial protein, suggesting that the undetectable tRNA genes in the mt-genome may be nuclear- encoded and imported from the cytoplasm. Comparing the two mt-genome structures, no differences were found between the two mt-genomes analyzed in terms of gene content, gene order and the direction for the translation of each gene. However, in a comparison of differences in sequence between the two mt- genomes, multiple small-size insertions/deletions and point mutations were found mainly in the interspacer region of genes, some of which produced new restriction sites. Moreover, large fragments of insertions/deletions longer than 1 kb were also found both in the interspacer regions of genes and in the intrageneric regions, where there were different intronic sequences. This indicates, in particular, that the difference of intronic sequences contained each mt-genome is the primary basis for the production of the RFLP observed in both. Less