Sequencing And Analyzing Mitochondrial Genome Of Cacopsylla Coccinea

Based on the academic importance of Cacopsylla coccinea, the current study aims at revealing its phylogenetic status in Homoptera. The complete mitochondrial (mt) genome of C. coccineae was sequenced and the phylogenetic tree was built. The results are as follows:The complete mitochondrial (mt) genome of C. coccineae was sequenced. The present study sequenced the complete mitochondrial (mt) genome of C. coccineae, with a full length of 14,832 bp:1) The mt includes 13 encoded protein genes,22 transferred RNA genes,2 ribosomal RNA genes, and 1 non-coding region with high AT content; 2) This mt genome has 16 intergenic regions (full length 235 bp,1-51 bp interval) and 10 gene overlaps (full length 83 bp, overlapping between 1-41 bp); 3) AT content in the complete genome, rRNA and PCGs is 72.04%,77.06% and 70.05% respectively, with AT content on 3rd-site codon highest,2nd-site L codon higher than other sites, rating 79.65%; 4) AT-deviation skew GC-deviation skew in protein coded gene were both negative; 5) ATN as the start codon, complete TAG and TAA as end codon, with incomplete T occasionally; 6) Amino acid consists of 6 hydrophobic benzoylalanine, methionine, leucine, isoleucine, serine and valine; 7) The longest rRNA has 72bp, and the shortest 54 bp, all can fold into a typical cloverleaf structure except trnSl, furthermore, the secondary structure of tRNA appears to lack the sequence to code T-or D-arm, with base mismatches at the same time.Based on C. coccineae, Paratrioza sinica and Pachypsylla venusta, with comparative genomics and bioinformatics, we analyzed the molecular composition features of Psyllidae genome, and the results are as follows:1) The size is similar; 2) Compared with the other two, trnV gene in C. coccineae rearranged; 3) P. venusta has the longest interval and P. sinica, the largest overlap; 4) AT content among the three is similar, with about 70%; 5) Mismatch exists among the three, with AT content of 3rd-site codon in H-strand and L-strand highest; 6) Nad 5, nad6 and cob genes have less than one base substitution rate, which shows they are under negative selection.Based on the 27 species of Homoptera, with Maximun likelihood(ML) and Bayesian inference(BI), the two data sets (rRNA and PCGs) were analyzed to construct the phylogenetic relationship. The results are:the ML and BI trees based on 2 data sets (PCG and rRNA) are almost the same, which helps species of the same family gather together. Comparing the two data sets rRNA and PCGs, trees based on PCGs are more reliable, the possible reason here is trees on rRNA are much too quick for the classification.