In this study, the mitogenomes of two Paxillus species were assembled, annotated and compared. The two mitogenomes of Paxillus involutus and P. rubicundulus comprised circular DNA molecules, with the size of 39,109 bp and 41,061 bp, respectively. Evolutionary analysis revealed that the nad4L gene had undergone strong positive selection in the two Paxillus species. In addition, 10.64 and 36.50% of the repetitive sequences were detected in the mitogenomes of P. involutus and P. rubicundulus, respectively, which might transfer between mitochondrial and nuclear genomes. Large-scale gene rearrangements and frequent intron gain/loss events were detected in 61 basidiomycete species, which revealed large variations in mitochondrial organization and size in Basidiomycota. In addition, the insertion sites of the basidiomycete introns were found to have a base preference. Phylogenetic analysis of the combined mitochondrial gene set gave identical and well-supported tree topologies, indicating that mitochondrial genes were reliable molecular markers for analyzing the phylogenetic relationships of Basidiomycota. This study is the first report on the mitogenomes of Paxillus, which will promote a better understanding of their contrasted ecological strategies, molecular evolution and phylogeny of these important ectomycorrhizal fungi and related basidiomycete species.

中文翻译：

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两种外生菌根真菌（Paxillus）的比较线粒体基因组分析揭示了担子菌的基因重排、内含子动力学和系统发育。


在这项研究中，对两种柱状芽孢杆菌物种的有丝分裂基因组进行了组装、注释和比较。 Paxillus involutus 和 P. rubicundulus 的两个有丝分裂基因组由环状 DNA 分子组成，大小分别为 39,109 bp 和 41,061 bp。进化分析表明，nad4L 基因在两个 Paxillus 物种中经历了强烈的正选择。此外，在P. involutus和P. rubicundulus的线粒体基因组中分别检测到10.64%和36.50%的重复序列，这些重复序列可能在线粒体和核基因组之间转移。在 61 个担子菌物种中检测到大规模基因重排和频繁的内含子获得/丢失事件，这揭示了担子菌门线粒体组织和大小的巨大变化。此外，还发现担子菌内含子的插入位点具有碱基偏好。组合线粒体基因集的系统发育分析给出了相同且得到充分支持的树拓扑，表明线粒体基因是分析担子菌门系统发育关系的可靠分子标记。这项研究是关于柱状菌线粒体基因组的第一份报告，这将有助于更好地了解这些重要的外生菌根真菌和相关担子菌物种的对比生态策略、分子进化和系统发育。