基于线粒体16SrRNA序列和线粒体基因组裂化程度分析吸虱亚目系统发育
Phylogeny of the Anoplura based on variation in 16SrRNA sequences and the extent of mitochondrial genome fragmentation in this group
李 伟 陈 婷 董文鸽
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DOI：10.7679/j.issn.2095-1353.2020.140
作者单位：大理大学实验室管理处，大理 671003；大理大学病原与媒介生物研究所，下关 671000
中文关键词：吸虱亚目；16SrRNA；线粒体基因组裂化；系统发育
英文关键词：Anoplura; 16SrRNA; mitochondrial genome fragmentation; phylogeny
中文摘要：
【目的】 吸虱亚目是真兽类哺乳动物体表的专性吸血寄生虫和潜在的病原传播媒介昆虫。吸虱亚目线粒体基因组具有不同于两侧对称动物线粒体基因组传统认识的典型性，其线粒体基因组呈现出剧烈的裂化现象，形成多个线粒体微环染色体。目前针对吸虱亚目16SrRNA基因序列和线粒体基因组裂化程度分析吸虱亚目系统发育的研究很少，亟需对吸虱亚目的亲缘关系进行研究和探讨。【方法】 采用非加权组平均法（UPGMA）、邻近法（NJ）和最大简约法（MP）对6科6属13种吸虱的16SrRNA基因长片段序列进行进化关系分析。采用高通量测序法测定2科2属4种吸虱的线粒体基因组，并分析5科5属10种吸虱线粒体基因组裂化程度与吸虱亚目的系统发育关系。【结果】 进化树结果表明吸虱的6个科均为单系群，猴虱科较另外5个科相对原始，结果支持形态分类地位。对5科5属10种吸虱线粒体基因组裂化程度分析结果表明裂化速率最快的是3种人虱（体虱、头虱和阴虱），最慢的是3种血虱（猪血虱、野猪血虱和驴血虱），4种鼠虱（亚洲多板虱、棘多板虱、红姬甲胁虱和克氏甲胁虱）处于中间。在进化树上，进化程度由低到高依次为血虱<鼠虱<人虱，与线粒体基因组裂化所显示的由慢到快的顺序一致。【结论】 系统进化树中不同谱系的吸虱基本上形成单系群，结果与形态学研究结果非常吻合。吸虱亚目线粒体基因组的裂化程度或许与类群（分类单元）的进化程度具有一致性。
英文摘要：
[Objectives] The Anoplura are sucking lice; obligate, hematophagous ectoparasites of eutherian mammals and potential vectors for pathogens that can cause severe infectious diseases in humans and other animals. The mitochondrial genome of the Anoplura is distinct from the traditional understanding of that of a bilateral animal. Extensive fragmentation is present in the mt genome forming multiple mini-circular mitochondrial chromosomes. Although a revision of the taxonomic status of the Anoplura is urgently required, there has so far been very little phylogenetic analysis of the group based on 16SrRNA sequence variation and mitochondrial genome fragmentation. [Methods] Phylogenetic relationships were inferred by comparing 16SrRNA gene sequences of 13 species from 6 genera and 6 families using the arithmetic mean (UPGMA), neighbor-joining (NJ) and maximum parsimony (MP), methods. The mitochondrial genomes of 4 species in 2 genera and 2 families were sequenced using the Illumina Hiseq 2000 platform, and the extent of mitochondrial genome fragmentation in 10 species from 5 genera and 5 families was analyzed. [Results] A phylogenetic tree supports the current morphological taxonomy in that the 6 families are monophyletic and the Pedicinidae the most primitive. The analysis of the extent of mitochondrial genome fragmentation in 10 species from 5 genera and 5 families shows that the 3 species of human lice (Pediculus humanus, Pediculus capitis and Pthirus pubis) are more fragmented than the 4 species of rat lice (Polyplax asiatica、Polyplax spinulosa、Hoplopleura kitti and Hoplopleura akanezumi). The 3 species of Haematopinus lice (Haematopinus suis, Haematopinus apri and Haematopinus asini) have the least degree of fragmentation. The phylogenetic tree indicates that the relative degree of evolutionary divergence can be ranked as: Haematopinus lice < rat lice < human lice, which is consistent with the extent of mitochondrial genome fragmentation from slow to fast. [Conclusion] A phylogenetic tree of the Anoplura based on variation in 16SrRNA gene sequences indicates that different lineages are basically monophyletic, and supports the current morphological taxonomy. The level of mitochondrial genome fragmentation in the Anoplura may be consistent with the divergence of taxa.