Evolutionary rates of mitochondrial sequences and gene orders in Spirurina(Nematoda)are episodic but synchronised  

作　　者：Hong Zou Hong-Peng Lei Rong Chen Fang-Lin Chen Wen-Xiang Li Ming Li Dong Zhang Ivan Jakovlic Gui-Tang Wang 

机构地区：[1]Key Laboratory of Aquaculture Disease Control,Ministry of Agriculture,State Key Laboratory of Freshwater Ecology and Biotechnology,Institute of Hydrobiology,Chinese Academy of Sciences,Wuhan 430072,China [2]State Key Laboratory of Grassland Agro-Ecosystem,Institute of Innovation Ecology,Lanzhou University,Lanzhou 730000,China [3]Bio-Transduction Lab,Wuhan 430075,China [4]University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Water Biology and Security》2022年第2期49-59,共11页水生生物与安全（英文）

基　　金：the National Natural Science Foundation of China(31970408);the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(2019QZKK0304);China Agriculture Research System of MOF and MARA(CARS-45).

摘　　要：In contrast to highly conserved mitogenomic architecture in most metazoan lineages,which indicates that rearrangement events are generally strongly selected against,a limited number of often unrelated lineages exhibit highly elevated architectural evolution rates.The underlying reasons for this discontinuity in the mitogenomic evolution remain unknown.Previously we sequenced the mitochondrial genome of the first Camallanoidea species,Camallanus cotti(Nematoda:Chromadorea:Spirurina:Camallanidae),and found that it exhibited a highly disrupted architecture.We hypothesised that disrupted architecture might be a synapomorphic feature of the sister-clades Camallanoidea and Dracunculoidea.In this study,we sequenced mitogenomes of three freshwater fish-parasitic nematodes:Camallanus lacustris(Camallanidae),and two Philometridae(Dracunculoidea)species,Clavinema parasiluri,and Philometra sp.In partial agreement with the working hypothesis,both Camallanoidea species had exceptionally large mitogenomes of 18–19 Kbp,albeit the underlying reasons differed:in C.lacustris it was the existence of a single enlarged noncoding region of5.5 Kbp.A segment of this region exhibited an inverted base composition skew,which is indicative of a sequence inversion or recombination event.Camallanidae is the second identified chromadorean(first for Spirurina)family that exhibits within-family protein-coding gene rearrangements,and the absence of trnL1 and trnF may be a synapomorphy for Camallanoidea.The underlying reason for the disrupted architecture of Camallanidae does not appear to be a particular event shared by their common ancestor,but rather an underlying mechanism that makes disruptive events more likely in this lineage.In disagreement with the working hypothesis,Spiruromorpha and Oxyuridomorpha exhibited even more highly rearranged gene orders and greater overall branch lengths than Camallanomorpha.However,withininfraorder architecture was highly conserved and leaf nodes very short.This indicates that common ancestors of Spiruromorp

关 键 词：Branch length Gene order rearrangement Inversion Recombination Molecular clock Episodic evolution Camallanidae Philometridae Camallanomorpha 

分 类 号：Q178.1[生物学—水生生物学]