Determination Of The Mitochondrial Genome Of Five Grasshopper Si And Orthoptera Pedigree Genome Analysis

The complete mitochondrial genome(mitogenome) sequences for five species from Tettigonioidea,Ruspolia dubia,Conocephalus maculates,Gampsocleis gratiosa,Deracantha onos, and Elimaea cheni,were sequenced,assemblied,annotated,and compared with other known insect mitogenomes.An array of phylogenetic and phylogenomic techniques were used to infer the phylogenetic relationships among 30 orthopteran insects.Conclusions were showed below:1.The gene arrangement of R.dubia,C.maculates,G gratiosa,D.onos,and E.cheni mitogenome is identical to that of Gryllotalpa orientalis,Anabrus simplex and Drosophila yakuba, which implying that the translocation from trnK-trnD to trnD-trnK occurring only in the suborder Caelifera.2.The presence of 78 bp and 354 bp long intergenic spacer located between trnS^UCN and nadl,nadl and trnL^CUN is unique in the C.maculates mitogenome.3.The length of A+T-rich region in the R.dubia mitogenome was determined to be 70 bp, which was the shortest among Hexapoda.4.The putative initiation codon for coxl appears to be TTA in the R.dubia and E.cheni mitogenome.5.All nad5 have incomplete termination codon(T) in the R.dubia,C.maculates,G. gratiosa,D.onos,and E.cheni mitogenome.6.The usage of synonymous codon markedly correlated with the nucleotide composition at third codon position,and not the anticodon of tRNA in the mitogenome.Generally,the usage of codon that is A/T at the third codon position is higher than G/C.7.Some unmatched base pairs occur in the R.dubia,C.maculates,G gratiosa,D.onos and E.cheni tRNAs,and overwhelming majority of them are G-U pairs.8.The A+T content of the A+T-rich region was 70.6%,this value is lower than other regions in the E.cheni mitogenome.These values(71.4%and 67.4%) are slightly higher than the whole mitogenome and PCGs in the R.dubia and G gratiosa.This phenomenon indicated that the highly A+T content is not essential to A+T-rich region.9.T-stretch was found on the J and N strand of A+T-rich region in the C.maculates,G gratiosa and D.onos mitogenome,which is involved in the recognition of the O_R of mtDNA at least among holometabolous insects.10.Phylogenetic analysis confirmed a monophyletic Ensifera and Caelifera.Based on the comprehensive tree topologies,we can conclude that:1) the monophyly of Tettigonioidea, Grylloidea and Gryllotalpoidea was confirmed,and Grylloidea has a close relationship with Gryllotalpoidea than Tettigonioidea;2) the monophyly of Tettigoniidae was confirmed,and Tettigoniidae has a close relationship with Bradyporidae;3) there is disagreement in the monophyly of Conocephalidae,and additional samples or other molecular markers are needed to get further proof;4) the monophyly of Acridoidea was not supported;5) Chrotogonidae and Pyrgomorphidae has a close relationship with Tridactyloidea than other Acridoidea insects;6) the monophyly of Arcypteridae,Oedipodidae,Catantopidae and Acrididae was not be supported.