Determination Of Three Orthopteran Insect Mitochondrial Genome And Phylogenetic Analysis

The Mitochondrial DNA with the properties of high polymorphism,rapid evolutionary rate,maternal inheritance and almost lack of intermolecular genetic recombination,makes it as a good model for research in the field of phylogenetic reconstruction,pedigree biogeography,population structure and molecular evolution.Upto now,there were 1511 metazoan species which the mitochondrial genomes had been sequenced,including 127 Hexapods,of which 17 species from Orthoptera.In order to study the phylogenomic relationship of Orthoptera or Polyneoptera,the more research need for mitochondrial genome in various groups from Orthoptera.In this study,the complete mitochondrial genome sequence of three Orthoptera species was determined using long PCR and conserved primer walking approaches,and compared with other known insect mitogenomes.The complete sequences of two mitochondrial ribosomal RNA genes were used to infer the phylogenetic relationships among 33 orthopteran insects.Conclusions were showed below:1.The size of mitochondrial genomes of Sinotmethis amicus,Leuconemacris Iitangensis and Aeropus licenti Chang are 15802,15579,15597,respectively.They all have a conserved set of 37 genes and a control region.The gene order of the three species is the same as that in the Locusta migratoria which has a KD reset.2.The A+T omposition of mitochondrial genomes of Sinotmethis amicus,Leuconemacris Iitangensis and Aeropus licenti Chang are 72.7%,75.3%,74.8%,respectively.3.Most protein genes use the typical start codon ATN,except Sinotmethis amicus,Leuconemacris Iitangensis's COⅠgene use special start codon ACG,and Aeropus licenti Chang use ATTA as start cond.Most protein genes use the typical and complete stop codon:TAA or TAG except ND5 gene of Leuconemacris Iitangensis and ND5 of Aeropus licenti Chang,which use the incomplete stop codons:T.4.All the 22 tRNA genes of Sinotmethis amicus,Leuconemacris Iitangensis and Aeropus licenti Chang mitochondrial genomes have a typical clover leaf structure except tRNA Ser(AGN), which lack the DHU arm.Some unmatched base pairs occur in the Sinotmethis amicus,Leuconemacris litangensis and Aeropus licenti Chang tRNAs,and overwhelming majority of them are G-U pairs.5.The phylogenetic relationships of Orthoptera were reconstructed with rRNA genes by MP,ML and Bayesian inference.Phylogenetic analyses from the rRNA genes support the monophyly of Orthoptera,Grylloidea and Tettigonioidea is supported by all data.The monophyly of Arcypteridae,Oedipodidae,Catantopidae and Acrididae was not supported.Pyrgomorphidae and Chrotogonidae have closely relationships,and were the most ancestral groups among the 7 families of Acridoidea.Aeropus licenti Chang as the only representative data of Gomphoceridae, havs closely relationship with Arcypteridae.