Characterization Of The Complete Mitochondrial Genomes Of Cryptolestes Ferrugineus And Cryptolestes Turcicus And Their Phylogenetic Analysis

Cryptolestes ferrugineus and C. turcicus(Coleoptera: Laemophloeidae) are worldwide secondary feeder pest of stored products, infesting mainly broken or milled grain. Recently, there were some important researches done on its biology, ecology and behavioral characteristics. But a few study focused on its genetic characteristics, only mt DNA COI gene were used in molecular analysis study. There is no research involved in its complete mitogenome. Therefore, the mitochondrial genomes of C. ferrugineus and C. turcicus are not only considered as natural resources, but also in favor of species identification and phylogenetic analyses of Laemophloeidae. In this study, we presented the mitochondrial genome of C. ferrugineus and C. turcicus by Long-PCR. The complete mitochondrial genomes of them were sequenced, annotated and analyzed through various biosoftwares. Finally, 13 protein coding genes(PCGs) and 2 r RNA genes among 24 species of agricultural insect in Coleoptera were combined and then applied to constructe 3 different trees seperately by maximum likelihood(ML) and neighbor joining method(NJ) in Mega 6.0 as well as bayesian inference methods(BI) in Mr Bayes. The conclusios were presented as below:1. The complete mitochondrial genomes of C. ferrugineus and C. turcicus were 15, 511 and 15, 517 bp, both contained 13 protein coding genes, 2 r RNA, 22 t RNA as well as an AT rich region as descrided in other Coleoptera insects. The highly AT biased with the AT contents of 76.5%, 76.9% were observed in C. ferrugineus and C. turcicus mitogenomes.2. All 13 PCGs of the two Cryptolestes species start with ATN while various terminate codons were observed, including complete termination codon(TAA or TAG) and incomplete termination codon(TA or T).3. The size of 22 t RNA genes in both mitogenomes ranged from 60 to71 bp. It is noteworthy that t RNAser(AGN)genes could not be folded as standard cloverleaf structure as other t RNA genes in both mitogenomes, and the mismacth was common in t RNA genes. There were 28 and 21 mismacthes in C. ferrugineus and C. turcicus mitogenomes..4. AT rich region in C. ferrugineus mitogenome was 859 bp with an AT content of 86.5% while it was 857 bp in C. turcicus mitogenome with the AT content of 86.0%. The two rich regions contained many special structure, such as Ploy-A, Ploy-T and(TA) n,(AT) n.5. All of 3 phylogenetic trees shown that Laemophloeidae was grouped with Cucujoidea insects first, then grouped with other Coleoptera insects. The result shows that Laemophloeidae is sister to Cucujoidea and it is different from the previous traditional classification system.