Zheng Than The Grasshopper Mitochondrial Genome Analysis And Evolution Of Mitochondrial Genomes Of Orthoptera Insects With Wing-type And Type Of Ecological Research

Up to the end of April 2011, there have been 240 Isecta mitochondrial genomic sequences recoded in the NCBI, but there are only 36 Orthoptera mitochondrial genomic sequences, and havn't Eumastacoidea mitochondrial genomic sequences so far. In this paper, the complete mitochondrial genomes of Pielomastax zhengi was sequenced, assemblyed, annotated and analyzed in details with the strategies of long-PCR and sub-PCR. The new mitochondrial genome combined with that of other Orthoptera species which completed mitochondrial genome were sequenced in our laboratory, as well as other insects deposited in GenBank, total 50 Isecta mitochondrial genomic sequences. MP trees, MLtrees and BI trees were constructed for the four data sets. The 50 insects were divideded into longipennate insects, brachypterous insects and apterous insects according to wings. And The 50 insects were divideded into arboreal insects, grass habitat insects, and ground-living insects. We have analysised the dN/dS, dN and dS of 3 kinds of different wings insects and 3 kinds of different Ecological insects. The conclusions drawn from above study as follows:1. The mitochondrial genomes of Pielomastax zhengi is 15602 bp. They encode 13 protein genes,22 tRNA genes,2 rRNA genes and a D-loop area. The A+T content of Pielomastax zhengi is 71.8%. The ATG start codon is usually used by the 13 protein genes, followed are ATC and ATT. In addition to the TAG is stop codon of COIII, ND3, CytB and ND1,and stop codon of ND5 is incomplete termination codon (T). The stop codon of the remaining protein genes is TAA. In addition to the tRNASer(AGN),22 tRNA genes all have typical clover leaf structure,but we get only 16 secondary structure of tRNA in Pielomastax zhengi by online forecast, the remaining 6 secondary structure of tRNA in Pielomastax zhengi were forecasted by people.we forecast 2 secondary structure of rRNA in Pielomastax zhengi according to 2 secondary structure of rRNA in Locusta migratoria tibetensis. At last we found that 2 secondary structure of rRNA in Pielomastax zhengi more similar to 2 secondary structure of rRNA in Acridoidea. We found a T stretch in D-loop area of Pielomastax zhengi, and it can form a stem-loop structure, which is related with the origion replication of the N chain.2. In this paper the 12 phylogenetic trees were analysised then we found that 3 kinds of approachs of Constructing phylogenetic trees have some differences, but These differences are very small, especially, MLtrees and BI trees almost are same. And we found that 37 genes data sets and 13 PCGs data sets could construct phylogenetic trees for between High-order element and between lower-order element, but the other 2 data sets only could construct phylogenetic trees for between lower-order element. all of insects of suborder Caelifera Clustered into together in all of phylogenetic trees, and all of insects of suborder Ensifera Clustered into together in most of phylogenetic trees.8 insects of Tettigonioidea and 32 insects of Acridoidea Clustered into together respectively in most of phylogenetic trees, so they are all monophyletic groups. Tridactylus japonicus in the base of phylogenetic trees in suborder Caelifera, and Pielomastax zhengi in the penullimate of phylogenetic trees in suborder Caelifera.3. The Ka/Ks value of apterous insects was 29.8%(p=0.249) higher than the Ka/Ks value of brachypterous insects; the Ka/Ks value of brachypterous insects was 16.8%(p=0.326) higher than the Ka/Ks value of longipennate insects; the Ka/Ks value of apterous insects was 51.6%(p=0.016) higher than the Ka/Ks value of longipennate insects, and have reached a statistically significant level, so different winged insects have experienced different selective pressures. Comparisons of Ka/Ks value among 3 different ecotype insects found that the grass habitat of insects and the ground-living insects have accumulated more non-synonymous mutations than the arboreal insects, so all of insects have experienced different selective pressures, and the evolution of the 50 insects isn't neutral.