The Complete Mitochondrial Genomes Of Three Moth Species And Phylogenies Of The Relevant Ditrysia(Lepid Optera:Glossata)Groups

The Ditrysia is one of the lepidopteran groups which is subordinated to suborder Glossata,containing about 99%species of all moths and butterflies,and up to date,there are already over 157 000 ditrysian species were described around the world.Most ditrysian insects are closely related to the activities of productions and livings of humanbeings and play an important role in the maintainence of natural ecosystems.In addition,some of them have become as the main subjects and even as the model organisms in entomological and evolutionary study areas.However,up to the present,the Ditrysia overall phylogeny,especially the deep-level phylogeny has not been fully resovled,mainly attributed to the conflictions between the results of morphological and molecular criteria.The complete mitochondrial genome?mitogenome?of insects is a covalent closed looped molecule with a size of about 15¹9 kb,usually harboring 13 protein coding genes?PCGs?,two ribosomal RNA genes,about 22 transfer RNA genes and a noncoding AT-rich region.Owing to its relatively small size,genetically rich information,maternal inherence and so on,the mitochondrial genome sequence data have been widely used in the studies of molecular evolution and phylogeny of insects and some other related animal groups.In this study,we firstly reported the complete mitogenome of the three ditrysta insect species,namely the Pidorus atratus?Zygaenoidea?,Oreta fuscopurpurea?Drepanoidea?and Sideridis albicosta?Noctuoidea?,and compared them with details with other known Ditrysta insects mitogenome sequence data.Additionally,we reconstructed the phylogenetic trees of total 72 examplar Ditrysta species based on the mitogenomic sequence data of 13 protein-coding genes with the maximum likelihood?ML?and Bayesian inference?BI?methods,in order to further clarify the phylogenetic relationships among the main ditrysian groups.At the same time,we reconstructed the phylogenetic trees of the representative species of superfamilies Zygaenoidea,Drepanoidea and Noctuoidea separately,based on the different mitochondrial gene sequence dataset available from the GenBank,in order to investigate the phylogenetic relationships of main lineages within the three superfamilies,respectively.The results of comparative mitogenome analysis showed that the mitogenomes of the Pidorus atratus,the Oreta fuscopurpurea and the Sideridis albicosta are 15383 bp,15564 bp and 15320 bp in size,respectively.All of the three complete mitogenomes contain 13 protein coding genes?PCGs?,22 transfer RNA genes?tRNAs?,two ribosomal rRNA genes?rRNAs?and a non-coding AT-rich region.Among them,the gene order and direction of the Oreta fuscopurpurea and the Sideridis albicosta mitogenomes are consistent with those of most other ditrysian species known,but the gene rearrangement between genes tRNA^Glu and tRNA^Ser?AGN?ocurring in the Pidorus atratus mitogenome,is also presented in the only published mitogenome of Zygaenidae species Rhodopsona rubiginosa?Genbank accession No.NC₀25761.1?.The arrangement of the two genes in most published ditrysian insects is tRNA^Ser?AGN?-tRNA^Glu which is encoded by the heavy chain,however,the gene order of the two known Zygaenidae species is tRNA^Glu-tRNA^Ser?AGN?,which is encoded by the light chain.This new gene arrangement is probably characteristic of Zygaenidae mitogenomes.All the PCGs of the three moth species use typical ATN as the starting codon,except of the COI gene using CGA as the starting codon;most PCGs use typical TAA as termination codon,with only a few taking incomplete T or TA as termination signals.In addition,some intergenic spacer sequences and overlapping sequences are scattered throughout the whole mitogenomes,that is,total 15,20 and 16 intergenic spacer sequences ranging from 1 bp to 58 bp,and 8,8 and 7 overlapping sequences ranging from 1 to 8 bp,are presented in the three mitogenomes respectively.Like other detected moth species,the nucleotide composition of the three ditrysian mitogenomes are obviously AT biased,with the mean values of about 80 percent.Bayessian inference?BI?and maximum likelihood?ML?phylogenetic trees of Ditrysia reconstructed by incorporating the first complete sequence of Drepanidae species newly reported in this study showed that the phylogenetic relationships among the 16 ditrysian superfamilies are as follows:?Tineoidea+??Yponomeutoidea+Gracillariidae?+??Copromorphoidea+Tortricoidea?+??Cossoidea+Thyridoidea?+Zygaenoidea?+?Gelechioidea+??Papilionoidea+Hesperioidea?+?Pyraloidea+?Drepanoidea+Bombycoidea+?Noctuoidea+Geometroidea????????.The reconstructed Bayesian inference?BI?tree of the Zygaenoidea,Drepanoidea and Noctuoidea based on the combined sequence dataset of mitochondrial ND1,16S and 12S rRNA genes showed that the phylogeneticrelationshipofZygaenoideaisasfollows:(?Himantopteridae+Somabrachyidae?+?Limacodidae+???Heterogynidae+Phaudidae?+Lacturidae??+Zygaenidae?,with the Zygaenidae internal phylogeny being?Zygaeninae+?Procridinae+?Callizygaeninae+Chalcosiinae???.The reconstructed maximum likelihood?ML?and neighbor-joining?NJ?trees of Drepanidae based on combined mitochondrial COI and ND1 gene sequence data showed that the phylogenetic relationship of Drepanoidea is as follows:?Epicopeiidae+?Cyclidiinae+Thyatirinae?+?Oretinae+Drepaninae??.The reconstructed ML tree and BI trees of the Noctuidae based on 13 PCG both showed that the phylogenetic relationship of the Noctuidae is as follows:((Notodontidae+?Erebidae+?Nolidae+?Euteliidae+noctuidae???,with the Lymantridae fallen within the family Erebidae.