Mitochondrial genome fragmentation unites the parasitic lice of eutherian mammals

Organelle genome fragmentation has been found in a wide range of eukaryotic lineages; however, its use in phylogenetic reconstruction has not been demonstrated. We explored the use of mitochondrial (mt) genome fragmentation in resolving the controversial suborder-level phylogeny of parasitic lice (order Phthiraptera). There are ~5,000 species of parasitic lice in four suborders (Amblycera, Ischnocera, Rhyncophthirina and Anoplura), which infest mammals and birds. The phylogenetic relationships among these suborders are unresolved despite decades of studies. We sequenced the mt genomes of eight species of parasitic lice and compared them with 17 other species of parasitic lice sequenced previously. We found that the typical single-chromosome mt genome is retained in the lice of birds but fragmented into many minichromosomes in the lice of eutherian mammals. The shared derived feature of mt genome fragmentation unites the eutherian mammal lice of Ischnocera (family Trichodectidae) with An...

细胞器基因组碎片化（Organelle genome fragmentation）已在广泛的真核生物类群中被发现，但其在系统发育重建中的应用尚未得到证实。本研究探讨了线粒体（mt）基因组碎片化在解析寄生虱（虱目Phthiraptera）存在争议的亚目水平系统发育关系中的应用。寄生虱共计约5000个物种，隶属于4个亚目：钝角亚目（Amblycera）、丝角亚目（Ischnocera）、象虱亚目（Rhyncophthirina）以及吸虱亚目（Anoplura），均寄生于哺乳类与鸟类。尽管历经数十年研究，这些亚目间的系统发育关系仍未明确。我们对8种寄生虱的线粒体基因组进行了测序，并与此前已测序的17种寄生虱进行比对分析。研究发现，鸟类寄生虱仍保留典型的单染色体线粒体基因组，而真兽类哺乳动物寄生虱的线粒体基因组则碎裂为众多微染色体。线粒体基因组碎片化这一共有衍征（shared derived feature），将丝角亚目（毛首虱科Trichodectidae）的真兽类哺乳动物寄生虱与An...