Three Catantopinae Mitochondrial Genome Sequencing And Phylogenetic Relationship Of Locust Suborder Analysis

Up to May 2009,there have been 2084 Metazoan mitochondrial genomic sequences published in the NCBI,including 209 species from Hexapoda,19 species from Orthoptera,and 10 species from Caelifera.Although the number of the mtgenomes has been increased year by year,it is still difficult to show the relation of Caelifera.The complete mitochondrial genome(mitogenome) sequences for three species from Catantopidae,Hieroglyphus annulicornis,Choroedocus violaceipes and Caryanda elegans were sequenced,assemblied,annotated,and compared with that of Locusta migratoria.Conclusions were showed below:1.The complete mitochondrial genomes of Hieroglyphus annulicornis,Choroedocus violaceipes and Caryanda elegans are 15445bp,15977bp and 15459bp in size,respectively.They all encodes 13 PCGs,22 tRNAs.2 rRNAs and a A+T-rich region located between SrRNA and tRNA^Ile.Their gene order is identical with the published Caelifera species.2.The base composition of the three species has obvious bias with AT content 73.8%,73.3%and 74.9%respectively.The A+T contents of the A+T-rich region in Hieroglyphus annulicornis, Choroedocus violaceipes and Caryanda elegans are 85.3%,86.7%and 85.1%,respectively, which are obviously higher than their own whole mitochondrial genome and protein-coding genes.3.The start codons of COX1 in Hieroglyphus annulicornis,Choroedocus violaceipes and Caryanda elegans are putative ACC,CCG,and ATC,respectively.The NAD4 in Hieroglyphus annulicornis and the NAD5 in Choroedocus violaceipes and Caryanda elegans are all ended with the incomplete termination codon(T).4.All of 22 tRNAs in Hieroglyphus annulicornis,Choroedocus violaceipes and Caryanda elegans can fold into the typical clover structure except the tRNAS^AGN,which lacks the D-stem.The secondary structures of 22 tRNAs have all some unmatched base pairs.The G-U pairs are the main mismatches.5.The A+T-rich regions in Hieroglyphus annulicornis,Choroedocus violaceipes and Caryanda elegans do not exist the repeative regions as that of Locusta migratoria,but can all be divided into 8 conserved blocks and exist the secondary structure of the E regions just as the blocks in Oxya chinenis.The upstream of the O_N(confirmed by LMPCR) in Locusta migratoria has not the POLY-T stretch exsting in holometabolous insects,but has a conserved secondary structure which is the same as the E- regions.The E-regions may be the main identitive structure in the upstream of the O_N in Caelifera.6.The SrRNA gene of Hieroglyphus annulicornis,Choroedocus violaceipes and Caryanda elegans is more conservetive than the LrRNA.The secondary structures of three SrRNA all contain 3 domains or 30 stem-loop structures,and the most difference are all in domainl nearing the A+T-rich region;The secondary structures of three LrRNA all contain 6 domains or 43 stem-loop structures,and domainⅢhas all only 20-30 bases.7.Using the data sets consist of 8 PCGs except atp8 in the J-strand,the A+T-rich region and the combination of the 8 PCGs and A+T-rich region of the 19 species as the molecular markers to reconstruct their phylogenetic relationships by the methods of the equal-weighted MP,ML and Mrbayesian methods.All 9 phylogenetic trees highly support several subfamilies's sister relationships,such as Locusta migratoria,Locusta migratoria migratoria within Locustinae, Chorthippus chinensis,Arcyptera coreana within Arcypterinae,which seems to show that these mitochondrial datas are more suitable to illustrate the monophyly of the subfamily.Based on the J-strand PCGs,8 species in Catantopidae are clustered into a clade in MP tree,whereas 7 species(not including Traulia stal) are clustered into a clade in ML and Mrbayesin trees,this seems to say that the PCGs data sets are suitable to testify the relation of the family.Among the three species used in this research,Caryanda elegans is the sister group of Oxya chinenis, Choroedocus violaceipes is the sister group of Calliptamus italicus,and Hieroglyphus annulicornis has not the specific existant sister group.