Mitochondrial Genome Of The Chinese Population Of Four Locusts Determination And Analysis

The complete mitochondrial genome (mitogenome) sequences from 4 Locusta migratoria populations in China, Locusta migratoria tibetensis, Locusta migratoria migratoria from Songpan, Locusta migratoria manilensis from Lincang and Shangri-la, were sequenced, assemblied, annotated and analysed with their genomic properties. An array of phylogenetic and phylogenomic techniques were used to infer the phylogenetic relationships among these 4 and other 3 populations. Conclusions were showed below:1. The mitogenome size of Locusta migratoria tibetensis, Locusta migratoria migratoria from Songpan, Locusta migratoria manilensis from Lincang and Shangri-la are 15903 bp,15898 bp, 15886 bp,15901 bp respectively. They all encode 13 protein genes,2 rRNA genes,22 tRNA genes and 1033～1034 bp A+T rich region.2. The average A+T content of mitogenomes, genome protein coding sequence, rRNA, tRNA gene and A+T rich region was corresponding well to the A+T bias generally observed in insect mitogenomes. The A+T content of Lincang population is 77.5%, is the highest A+T content among mitogenomes of the 4 populations, The A+T content of Locusta migratoria tibetensis is 75.3%, which is the lowest.3. The usage of synonymous codon markedly not correlated with the the anticodon of tRNA in the mitogenome, but with the nucleotide composition at third codon position. Generally, the usage of codon that is A/T at the third codon position is higher.4. The start codon of CO1 in Locusta migratoria tibetensis, Locusta migratoria migratoria from Songpan, Locusta migratoria manilensis from Lincang and Shangri-la are all ATTA. The ND5 in Locusta migratoria tibetensis, Locusta migratoria migratoria from Songpan, Locusta migratoria manilensis from Lincang and Shangri-la are all ended with the incomplete termination codon T. Other gene all started with ATN, and ended with TAA or TAG.5. Except tRNASer(S-AGN). which lack of the DHU arm, all the other tRNA genes of Locusta migratoria tibetensis, Locusta migratoria migratoria from Songpan, Locusta migratoria manilensis from Lincang and Shangri-la mitochondrial genomes have a typical clover leaf structure. Some unmatched base pairs occurred, and most of them are G-U pairs.6. The control region in mitogenome of Locusta migratoria tibetensis, Locusta migratoria migratoria from Songpan and Sinkiang, Locusta migratoria migratorioides, Locusta migratoria manilensis from Lincang, Shangri-la and Hainan all have the conserved blocks in (A+T) riched region Block A, Block B, Block E1, Block E2 and Block F. The sequence of Block E1 and Block E2 could form a stem-loop secondary structure, which participate in replication origin.7. Locusta migraioria migratorioides and Locusta migratoria tibetensis are sister groups. The 3 population of Locusta migratoria manilensis are not monophyletic groups. Locusta migratoria migratorioides and Locusta migratoria manilensis have the closest ancestor, which is different from Locusta migratoria migratoria.8. Phylogenetic analyses of the 7 populations support Songpan population and Sinkiang population as monophyletic groups. Songpan population should belong to Locusta migratoria migratoria, not Locusta migratoria manilensis.