The Aedes Buddha Locust And Gampsocleis Guo Grasshopper Mitochondrial Genome Sequencing And Analysis

Mitochondrial genome is widely used as the model for structural, functional and evolutionary genomics studies. Metazoan mtDNA is usually circular, 14-20 kb in length, encodes 37 genes: 22 transfer RNA genes, 13 protein-encoding genes and two ribosomal RNA genes (small and large subunit ribosomal RNAs - 12S rRNA and16S rRNA, respectively), and possesses one AT rich region. Mitochondrial genome of human was sequenced in 1981. With advancement of sequcening technique, more and more mitochondrial genome sequences were submitted to NCBI database. As of March 2008, complete mitochondrial genome sequences were available in Genbank for 1195 different species of animals. Of these, 115 are from insects, but only five from Orthoptera.In this study, motichondrial genomes of two Orthoptera species were sequenced using the strategy of sub-PCR after long-PCR amplification. We compared the two species with other Orthoptera insect from aspects of comparative genomics. We also use parts of mitochondrial genes to reconstruction Orthoptera phylogeny. The main cinclusions are summarized as follwing:1. The complete mitochondrial genome of P. albonema and G. sedakovii obscura are 15657bp and 15623bp respectively, including 13 protein genes, 22 tRNA genes, 2 rRNA genes, and an AT-rich region. The overall AT composition in P. albonema and G. sedakovii obscura are 74.1% and 64.9% respectively. In P. albonema, the genes overlap with a total of 41bp in 9 locations (1- 8bp at each location).The intergenic spacer sequences (126 bp) spread over 21 regions ranging in size from 1 to 20 bp. In G. sedakovii obscura, the genes overlap with a total of 197bp in 17 locations (1- 44bp at each location).The intergenic spacer sequences (121 bp) spread over 14 regions ranging in size from 1 to 21 bp.2. The arrangement of mitochondrial coding genes of six species (P. albonema, G. sedakovii obscura, Locusta migratoria, Gryllotalpa orientalis, Ruspolia dubia, and Oxya chinesis) were compared. The result shows that excluding G. orientalis and R .dubia, the other four species occurred KD inversion. G. sedakovii obscura with KD inversion is in Acridoidea probably caused by parallele evolution.3. The intergenic spacer of six species (P. albonema, G. sedakovii obscura, Locusta migratoria, Gryllotalpa orientalis, Ruspolia dubia, and Oxya chinesis) in mitochondrial genome were 21 locations, 14 locations, 16 locations, 11 locations, 14 locations and 17 locations respectively, their length were 126bp, 121 bp, 101 bp, 81bp, 86bp and 87bp respectively. The longest intergenic spacer sequences 20bp, 21bp, 19bp, 34bp, 22bp and 21bp respectively.4. The genes overlap of six species (P. albonema, G. sedakovii obscura, Locusta migratoria, Gryllotalpa orientalis, Ruspolia dubia, and Oxya chinesis) in mitochondrial genome were 9 locations, 17 locations, 10 locations, 7 locations, 13 locations and 14 locations respectively, their length were 41bp, 197bp, 42bp, 29bp, 56bp and 65bp respectively. The largest genes overlap sequences 8bp, 44bp, 10bp, 8bp, 8bp and 19bp respectively.5. The start codon and stop codon usages of six species (P. albonema, G. sedakovii obscura, Locusta migratoria, Gryllotalpa orientalis, Ruspolia dubia, and Oxya chinesis) were compared. In all start codons usages of six species, usage ratio of ATG is 56.4%, ATT is 21.79%, ATA is 10.3%, ATC is 7.7%, special codon is 3.4%; In all stop codons usages of six species, the most usage ratio is TAA (67.9%), then TAG (12.8%) and TAT (2.6%).6. The unmatched base pairs of six species (P. albonema, G. sedakovii obscura, Locusta migratoria, Gryllotalpa orientalis, Ruspolia dubia, and Oxya chinesis) in tRNA secondary structures were compared, the number of unmatched base pairs are 32pairs, 43 pairs, 5 pairs, 34 pairs, 37 pairs and 29 pairs respectively.7. The rRNA secondary structures of five species (P. albonema, G. sedakovii obscura, Apis mellifera, Atractomorpha sinensis, and Ruspolia dubia) were compared. We can find more exactly stable regions.8. The AT rich region of six species (P. albonema, G. sedakovii obscura, Locusta migratoria, Gryllotalpa orientalis, Ruspolia dubia, and Oxya chinesis) were compared, their length are 728bp, 912bp, 875bp, 920bp, 70bp and 562bp, their AT contents are 83%, 71.5%, 85.94%, 74.89%, 71.4% and 86.6% respectively.9. Phylogenetic analysis from the CYTB, ATP6 and ATP8 genes all support the closely relationship of Gryllotalpoidea and Gryllotalpoidea etc, but they all don't support Ensifera as monophyletic groups. However, phylogenetic analysis of 13 protein coding genes in mitochondrial genome support two suborder Caelifera and Ensifera as monophyletic groups. Comparing with phylogenetic analysis of 13 protein coding genes in mitochondrial genome, the result shows that phylogenetic analysis of single gene may not correctly solve phylogenetic relationship of the higher taxa.